A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease

Randomised controlled trial of lifestyle interventions for abdominal obesity in primary health care

AIM

Assess effects on waist circumference from diet with or without cereal grains and with or without long-term physical exercise.

BACKGROUND

Elevated waist circumference is an indicator of increased abdominal fat storage and is accordingly associated with increased cardiovascular mortality. This is likely due to the association between lifestyle-induced changes in waist circumference and cardiovascular risk factors. Reductions in waist circumference may be facilitated by diet without cereal grains combined with long-term physical exercise.

METHODS

Two-year randomised controlled trial with factorial trial design in individuals at increased risk of cardiovascular disease with increased waist circumference. Participants were allocated diet based on current Swedish dietary guidelines with or without cereal grains (baseline diet information supported by monthly group sessions) and with or without physical exercise (pedometers and two initial months of weekly structured exercise followed by written prescription of physical activity) or control group. The primary outcome was the change in waist circumference.

FINDINGS

The greatest mean intervention group difference in the change in waist circumference among the 73 participants (47 women and 26 men aged 23-79 years) was at one year between participants allocated a diet without cereal grains and no exercise and participants allocated a diet with cereal grains and no exercise [M = -5.3 cm and -0.9 cm, respectively; mean difference = 4.4 cm, 4.0%, 95% CI (0.0%, 8.0%), P = 0.051, Cohen's d = 0.75]. All group comparisons in the change in waist circumference were non-significant despite the greatest group difference being more than double that estimated in the pre-study power calculation. The non-significance was likely caused by too few participants and a greater than expected variability in the change in waist circumference. The greatest mean intervention group difference strengthens the possibility that dietary exclusion of cereal grains could be related to greater reduction in waist circumference.

Diet in secondary prevention: the effect of dietary patterns on cardiovascular risk factors in patients with cardiovascular disease: a systematic review and network meta-analysis

BACKGROUND

Improving dietary habits is a first-line recommendation for patients with cardiovascular disease (CVD). It is unclear which dietary pattern most effectively lowers cardiovascular risk factors and what the short- and long-term effects are. Therefore, this network meta-analysis compared the effects of popular dietary patterns on cardiovascular risk factors in patients with established CVD.

METHODS

A systematic search of PubMed, Embase, the Cochrane library, SCOPUS and Web of Science was conducted up to 1 April 2023. Randomized controlled trials (RCTs) comparing the effect of popular dietary patterns (Mediterranean, moderate carbohydrate, low glycemic index, low-fat and minimal dietary intervention) on cardiovascular risk factors (body weight, systolic blood pressure, lipids) in CVD populations were selected. A random-effects network meta-analysis was performed.

RESULTS

Seventeen RCTs comprising 6,331 participants were included. The moderate carbohydrate diet had the most beneficial effect on body weight (-4.6 kg, 95%CrI -25.1; 15.8) and systolic blood pressure (-7.0 mmHg 95%CrI -16.8; 2.7) compared to minimal intervention. None of the included dietary patterns had a favorable effect on low-density lipoprotein cholesterol. After 12 months, the effects were attenuated compared to those at < 6 months.

CONCLUSIONS

In this network meta-analysis of 17 randomized trials, potentially clinically relevant effects of dietary interventions on CV risk factors were observed, but there was considerable uncertainty due to study heterogeneity, low adherence, or actual diminished effects in the medically treated CVD population. It was not possible to select optimal dietary patterns for secondary CVD prevention. Given recent clinical trials demonstrating the potential of dietary patterns to significantly reduce cardiovascular event risk, it is likely that these effects are effectuated through alternative physiological pathways.

Nutritional Strategies for the Management of Type 2 Diabetes Mellitus: A Narrative Review

BACKGROUND

Thinking about greater adherence to dietary planning, it is extremely important to be aware of all nutritional strategies and dietary prescriptions available in the literature, and of which of them is the most efficient for the management of T2DM.

METHODS

A search was carried out in 2023 for randomized clinical trials, systematic reviews, meta-analyses, and guidelines in the following databases: Pubmed, Scielo, Web of Science, CrossRef and Google Scholar. In total, 202 articles were collected and analyzed. The period of publications was 1983-2023.

RESULTS

There is still no consensus on what the best nutritional strategy or ideal dietary prescription is, and individuality is necessary. In any case, these references suggest that Mediterranean Diet may of greater interest for the management of T2DM, with the following recommended dietary prescription: 40-50% carbohydrates; 15-25% proteins; 25-35% fats (<7% saturated, 10% polyunsaturated, and 10% monounsaturated); at least 14 g of fiber for every 1000 kcal consumed; and <2300 mg sodium.

CONCLUSIONS

Individuality is the gold standard for dietary prescriptions, however, the Mediterranean diet with low levels of carbohydrates and fats seems to be the most promising strategy for the management of T2DM.

Impact of Paleo Diet on Body Composition, Carbohydrate and Fat Metabolism of Professional Handball Players

The Paleo diet (PD) involves a restriction of carbohydrates and increased fat content (35% energy from carbohydrates, 35% energy from fats and 30% energy from protein). The aim of this study was to examine the effect of the PD on body composition, concentration of carbohydrates and lipids, as well as insulin, irisin, adiponectin and leptin in the blood. A total of 25 handball players were assigned to two groups: 14 in the experimental group (PD) and 11 in the control group (CD), using a PD and a rational diet, respectively. Analysis of body mass and body composition (body mass index, fat mass, lean body mass, fat-free mass, muscle mass, bone mineral content and bone mineral density), as well as blood concentration of metabolism markers (glucose, insulin, total cholesterol, HDL-cholesterol, non-HDL-cholesterol, LDL-cholesterol, triglycerides, free fatty acids, β-hydroxybutyrate, irisin, adiponectin and leptin), were determined at the beginning and after 4 and 8 weeks of nutritional intervention. Body mass was lower (p < 0.01), and adiponectin blood concentration was higher (p = 0.03) in the PD group at the end of the intervention. There were no changes (p ≥ 0.05) in body composition and blood levels of other biochemical markers in either group.

Dietary Models and Cardiovascular Risk Prevention in Pediatric Patients

Nutritional intervention is worldwide recognized as a first step treatment for subjects with increased cardiovascular risk and it is of utmost importance especially for children and adolescents. Currently scientific evidence supports the role of dietary patterns instead of simple single nutrients or foods in cardiovascular risk prevention. Indeed, the American Heart Association dietary guidelines have expanded beyond nutrients to dietary pattern, that comprise not only single food items but also behavioral or cultural habits of specific populations. The aim of our narrative review is to analyze the most frequently adopted dietary patterns in children and adolescents and to evaluate their effect on cardiovascular risk factors and in cardiovascular risk prevention. Literature review showed that children cannot be considered as little adults: nutritional intervention must always grant adequate growth and neurodevelopment before reaching the proposed goals, therefore dietary patterns considered heart-healthy for adult subjects might not be suitable for pediatric patients. Mediterranean diet, DASH diet, Nordic diet and some plant-based diets seem to be the most promising dietary patterns in terms of cardiovascular health in the developmental age, even if further studies are needed to better standardize and analyze their effect on growing up individuals.

Hunter-gatherer diets and activity as a model for health promotion: Challenges, responses, and confirmations

Beginning in 1985, we and others presented estimates of hunter-gatherer (and ultimately ancestral) diet and physical activity, hoping to provide a model for health promotion. The Hunter-Gatherer Model was designed to offset the apparent mismatch between our genes and the current Western-type lifestyle, a mismatch that arguably affects prevalence of many chronic degenerative diseases. The effort has always been controversial and subject to both scientific and popular critiques. The present article (1) addresses eight such challenges, presenting for each how the model has been modified in response, or how the criticism can be rebutted; (2) reviews new epidemiological and experimental evidence (including especially randomized controlled clinical trials); and (3) shows how official recommendations put forth by governments and health authorities have converged toward the model. Such convergence suggests that evolutionary anthropology can make significant contributions to human health.

The Paleolithic Diet

The promotion of healthy diets is likely one of the most cost-effective strategies for preventing a wide range of disorders, including cardiovascular disease, obesity, hypertension, and type 2 diabetes. The majority of present non-communicable chronic diseases are attributed to civilization, an abundance of food, and a lack of physical activity. According to the purported lifestyles of early humans, the paleolithic diet (PD) encourages the intake of wild animal and plant foods. In recent decades, the paleolithic diet has grown in popularity, particularly among younger populations and those with cardiometabolic syndrome and other chronic diseases. Due to the nutrition profile of the paleolithic diet, historical studies have postulated that hunter-gatherers (HGs) have slender physiques and were physically fit and devoid of chronic ailments such as cardiovascular diseases (CVDs). This review highlights the composition/constituent of the paleolithic diet along with an emphasis on current studies and evidence on the effectiveness of the paleolithic diet in mitigating chronic diseases.

Dietary management of dyslipidemia and the impact of dietary patterns on lipid disorders

Dyslipidemia is a major risk factor for atherosclerotic cardiovascular disease and a healthy lifestyle is the first line of therapy for treatment. A healthy dietary pattern is a cornerstone for treating elevated low-density lipoprotein-cholesterol (LDL-C) and triglycerides (TG), both of which are hallmarks of dyslipidemia. Much research has been conducted evaluating the effect of different dietary patterns on LDL-C and TG, both eucalorically and with weight loss. Herein we review studies that have evaluated the effects of different dietary patterns on LDL-C and TG. Within the context of a healthy dietary pattern, constituent food and nutrient intakes impact LDL-C and TG lowering. Food- and nutrient-based recommendations for lowering both LDL-C and TG, will also be reviewed. Finally, the suitability of popular diets for patients with dyslipidemia will be discussed. Lifestyle interventions, including dietary intervention, should be individualized and customized to patient preferences to achieve clinically relevant lipid/lipoprotein improvements.

Fad Diets: Facts and Fiction

The global prevalence of obesity is alarmingly high and is impacting both developed and underdeveloped countries, beyond the borders of ethnicity, sex, and age. On the other hand, the global interest in dieting has increased, and people are obsessed with certain fad diets, assuming them as a magic bullet for their long-term problems. A fad diet is a popular dietary pattern known to be a quick fix for obesity. These diets are quite appealing due to the proposed claims, but the lack of scientific evidence is a big question mark. Such diets are often marketed with specific claims that defy the basic principles of biochemistry and nutritional adequacy. These diets may have protective effects against obesity and certain chronic diseases like cardiovascular diseases, metabolic syndrome, and certain cancers. Limited evidence exists to support the proposed claims; rather certain studies suggest the negative health consequences of long-term adherence to such dietary patterns. Many fad diets have emerged in the previous few decades. This review article will explore the current evidence related to the health impacts of some most popular diets: Atkins diet, ketogenic diet, Paleolithic diet, Mediterranean diet, vegetarian diet, intermittent fasting and detox diet.

Heart-Healthy Diets and the Cardiometabolic Jackpot

This review highlights the key components of a heart-healthy diet and presents an evidence-based overview of recent research. Diets that increase plant-based food sources and healthy unsaturated fats consumption and limit foods that are processed and/or high in sodium, refined sugar, and saturated fat are recommended. Dietary modification can be supplemented with lifestyle-based therapies (eg, exercise, time-restricted eating) to maximize clinical benefit and achieve the "cardiometabolic jackpot." Physicians should take into account cultural preferences, affordability and accessibility of foods, and their patients' cultural values or expectations when recommending dietary interventions.

Effects of Diet, Lifestyle, Chrononutrition and Alternative Dietary Interventions on Postprandial Glycemia and Insulin Resistance

As years progress, we are found more often in a postprandial than a postabsorptive state. Chrononutrition is an integral part of metabolism, pancreatic function, and hormone secretion. Eating most calories and carbohydrates at lunch time and early afternoon, avoiding late evening dinner, and keeping consistent number of daily meals and relative times of eating occasions seem to play a pivotal role for postprandial glycemia and insulin sensitivity. Sequence of meals and nutrients also play a significant role, as foods of low density such as vegetables, salads, or soups consumed first, followed by protein and then by starchy foods lead to ameliorated glycemic and insulin responses. There are several dietary schemes available, such as intermittent fasting regimes, which may improve glycemic and insulin responses. Weight loss is important for the treatment of insulin resistance, and it can be achieved by many approaches, such as low-fat, low-carbohydrate, Mediterranean-style diets, etc. Lifestyle interventions with small weight loss (7–10%), 150 min of weekly moderate intensity exercise and behavioral therapy approach can be highly effective in preventing and treating type 2 diabetes. Similarly, decreasing carbohydrates in meals also improves significantly glycemic and insulin responses, but the extent of this reduction should be individualized, patient-centered, and monitored. Alternative foods or ingredients, such as vinegar, yogurt, whey protein, peanuts and tree nuts should also be considered in ameliorating postprandial hyperglycemia and insulin resistance. This review aims to describe the available evidence about the effects of diet, chrononutrition, alternative dietary interventions and exercise on postprandial glycemia and insulin resistance.

Low-carbohydrate versus balanced-carbohydrate diets for reducing weight and cardiovascular risk

BACKGROUND

Debates on effective and safe diets for managing obesity in adults are ongoing. Low-carbohydrate weight-reducing diets (also known as 'low-carb diets') continue to be widely promoted, marketed and commercialised as being more effective for weight loss, and healthier, than 'balanced'-carbohydrate weight-reducing diets.

OBJECTIVES

To compare the effects of low-carbohydrate weight-reducing diets to weight-reducing diets with balanced ranges of carbohydrates, in relation to changes in weight and cardiovascular risk, in overweight and obese adults without and with type 2 diabetes mellitus (T2DM).

SEARCH METHODS

We searched MEDLINE (PubMed), Embase (Ovid), the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science Core Collection (Clarivate Analytics), ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) up to 25 June 2021, and screened reference lists of included trials and relevant systematic reviews. Language or publication restrictions were not applied.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in adults (18 years+) who were overweight or living with obesity, without or with T2DM, and without or with cardiovascular conditions or risk factors. Trials had to compare low-carbohydrate weight-reducing diets to balanced-carbohydrate (45% to 65% of total energy (TE)) weight-reducing diets, have a weight-reducing phase of 2 weeks or longer and be explicitly implemented for the primary purpose of reducing weight, with or without advice to restrict energy intake.  DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts and full-text articles to determine eligibility; and independently extracted data, assessed risk of bias using RoB 2 and assessed the certainty of the evidence using GRADE. We stratified analyses by participants without and with T2DM, and by diets with weight-reducing phases only and those with weight-reducing phases followed by weight-maintenance phases. Primary outcomes were change in body weight (kg) and the number of participants per group with weight loss of at least 5%, assessed at short- (three months to < 12 months) and long-term (≥ 12 months) follow-up.

MAIN RESULTS

We included 61 parallel-arm RCTs that randomised 6925 participants to either low-carbohydrate or balanced-carbohydrate weight-reducing diets. All trials were conducted in high-income countries except for one in China. Most participants (n = 5118 randomised) did not have T2DM. Mean baseline weight across trials was 95 kg (range 66 to 132 kg). Participants with T2DM were older (mean 57 years, range 50 to 65) than those without T2DM (mean 45 years, range 22 to 62). Most trials included men and women (42/61; 3/19 men only; 16/19 women only), and people without baseline cardiovascular conditions, risk factors or events (36/61). Mean baseline diastolic blood pressure (DBP) and low-density lipoprotein (LDL) cholesterol across trials were within normal ranges. The longest weight-reducing phase of diets was two years in participants without and with T2DM. Evidence from studies with weight-reducing phases followed by weight-maintenance phases was limited. Most trials investigated low-carbohydrate diets (> 50 g to 150 g per day or < 45% of TE; n = 42), followed by very low (≤ 50 g per day or < 10% of TE; n = 14), and then incremental increases from very low to low (n = 5). The most common diets compared were low-carbohydrate, balanced-fat (20 to 35% of TE) and high-protein (> 20% of TE) treatment diets versus control diets balanced for the three macronutrients (24/61). In most trials (45/61) the energy prescription or approach used to restrict energy intake was similar in both groups. We assessed the overall risk of bias of outcomes across trials as predominantly high, mostly from bias due to missing outcome data. Using GRADE, we assessed the certainty of evidence as moderate to very low across outcomes.  Participants without and with T2DM lost weight when following weight-reducing phases of both diets at the short (range: 12.2 to 0.33 kg) and long term (range: 13.1 to 1.7 kg).  In overweight and obese participants without T2DM: low-carbohydrate weight-reducing diets compared to balanced-carbohydrate weight-reducing diets (weight-reducing phases only) probably result in little to no difference in change in body weight over three to 8.5 months (mean difference (MD) -1.07 kg, (95% confidence interval (CI) -1.55 to -0.59, I2 = 51%, 3286 participants, 37 RCTs, moderate-certainty evidence) and over one to two years (MD -0.93 kg, 95% CI -1.81 to -0.04, I2 = 40%, 1805 participants, 14 RCTs, moderate-certainty evidence); as well as change in DBP and LDL cholesterol over one to two years. The evidence is very uncertain about whether there is a difference in the number of participants per group with weight loss of at least 5% at one year (risk ratio (RR) 1.11, 95% CI 0.94 to 1.31, I2 = 17%, 137 participants, 2 RCTs, very low-certainty evidence).  In overweight and obese participants with T2DM: low-carbohydrate weight-reducing diets compared to balanced-carbohydrate weight-reducing diets (weight-reducing phases only) probably result in little to no difference in change in body weight over three to six months (MD -1.26 kg, 95% CI -2.44 to -0.09, I2 = 47%, 1114 participants, 14 RCTs, moderate-certainty evidence) and over one to two years (MD -0.33 kg, 95% CI -2.13 to 1.46, I2 = 10%, 813 participants, 7 RCTs, moderate-certainty evidence); as well in change in DBP, HbA1c and LDL cholesterol over 1 to 2 years. The evidence is very uncertain about whether there is a difference in the number of participants per group with weight loss of at least 5% at one to two years (RR 0.90, 95% CI 0.68 to 1.20, I2 = 0%, 106 participants, 2 RCTs, very low-certainty evidence).  Evidence on participant-reported adverse effects was limited, and we could not draw any conclusions about these.  AUTHORS' CONCLUSIONS: There is probably little to no difference in weight reduction and changes in cardiovascular risk factors up to two years' follow-up, when overweight and obese participants without and with T2DM are randomised to either low-carbohydrate or balanced-carbohydrate weight-reducing diets.

A score appraising Paleolithic diet and the risk of cardiovascular disease in a Mediterranean prospective cohort

Purpose

To assess the association between a score appraising adherence to the PaleoDiet and the risk of cardiovascular disease (CVD) in a Mediterranean cohort.

Methods

We included 18,210 participants from the Seguimiento Universidad de Navarra (SUN) cohort study. The PaleoDiet score comprised six food groups promoted within this diet (fruit, nuts, vegetables, eggs, meat and fish) and five food groups whose consumption is discouraged (cereals and grains, dairy products, legumes, culinary ingredients, and processed/ultra-processed foods). CVD was defined as acute myocardial infarction with or without ST elevation, non-fatal stroke and cardiovascular death. Cox proportional hazards models adjusted for potential confounders were fitted to assess the association between the PaleoDiet score and CVD risk, and the PaleoDiet and MedDiet indices to explore differences between both diets.

Results

During 12.2 years of follow-up, 165 incident CVD cases were confirmed. A significant inverse association was found between the PaleoDiet score and CVD (HR Q5 vs. Q1: 0.45, 95% CI 0.27–0.76, P for trend = 0.007). A weaker association that became non-significant was observed when the item for low consumption of ultra-processed foods was removed from the score. Joint analysis of PaleoDiet and MedDiet Trichopoulou scores suggested that the inverse association between PaleoDiet and CVD was mainly present when adherence to the MedDiet was also high (HR for high adherence vs low adherence to both diet scores: 0.22, 95% CI 0.08–0.64).

Conclusions

Our findings suggest that the PaleoDiet may have cardiovascular benefits in participants from a Mediterranean country. Avoidance of ultra-processed foods seems to play a key role in this inverse association.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02696-9.

Personalized Postprandial Glucose Response-Targeting Diet Versus Mediterranean Diet for Glycemic Control in Prediabetes

OBJECTIVE

To compare the clinical effects of a personalized postprandial-targeting (PPT) diet versus a Mediterranean (MED) diet on glycemic control and metabolic health in prediabetes.

RESEARCH DESIGN AND METHODS

We randomly assigned adults with prediabetes (n = 225) to follow a MED diet or a PPT diet for a 6-month dietary intervention and additional 6-month follow-up. The PPT diet relies on a machine learning algorithm that integrates clinical and microbiome features to predict personal postprandial glucose responses. During the intervention, all participants were connected to continuous glucose monitoring (CGM) and self-reported dietary intake using a smartphone application.

RESULTS

Among 225 participants randomized (58.7% women, mean ± SD age 50 ± 7 years, BMI 31.3 ± 5.8 kg/m², HbA_1c, 5.9 ± 0.2% [41 ± 2.4 mmol/mol], fasting plasma glucose 114 ± 12 mg/dL [6.33 ± 0.67 mmol/L]), 200 (89%) completed the 6-month intervention. A total of 177 participants also contributed 12-month follow-up data. Both interventions reduced the daily time with glucose levels >140 mg/dL (7.8 mmol/L) and HbA_1c levels, but reductions were significantly greater in PPT compared with MED. The mean 6-month change in "time above 140" was -0.3 ± 0.8 h/day and -1.3 ± 1.5 h/day for MED and PPT, respectively (95% CI between-group difference -1.29 to -0.66, P < 0.001). The mean 6-month change in HbA_1c was -0.08 ± 0.19% (-0.9 ± 2.1 mmol/mol) and -0.16 ± 0.24% (-1.7 ± 2.6 mmol/mol) for MED and PPT, respectively (95% CI between-group difference -0.14 to -0.02, P = 0.007). The significant between-group differences were maintained at 12-month follow-up. No significant differences were noted between the groups in a CGM-measured oral glucose tolerance test.

CONCLUSIONS

In this clinical trial in prediabetes, a PPT diet improved glycemic control significantly more than a MED diet as measured by daily time of glucose levels >140 mg/dL (7.8 mmol/L) and HbA_1c. These findings may have implications for dietary advice in clinical practice.

The associations of the Palaeolithic diet alone and in combination with lifestyle factors with type 2 diabetes and hypertension risks in women in the E3N prospective cohort

PURPOSE

Patterns of change from the traditional Palaeolithic lifestyle to the modern lifestyle may partly explain the epidemic proportions of non-communicable diseases (NCDs). We investigated to what extent adherence to the Palaeolithic diet (PD) and the Palaeolithic-like lifestyle was associated with type 2 diabetes (T2D) and hypertension risks.

METHODS

A study of 70,991 women from the E3N (Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale) cohort, followed up for nearly 20 years. There were 3292 incident T2D and 12,504 incident hypertension cases that were validated. Dietary data were collected at baseline in 1993 via a food frequency questionnaire. The PD score and the Palaeolithic-like lifestyle score (PD, physical activity, smoking status, and body mass index [BMI]) were derived and considered in quintiles. Multivariable Cox regression models were employed to estimate hazard ratios (HR) and 95% confidence intervals (CI) for incident T2D and hypertension.

RESULTS

In the fully adjusted models, a 1-SD increase of the PD score was associated with 4% and 3% lower risks of T2D and hypertension, respectively. Those in the highest versus the lowest quintile of the score had HR (95% CI) of 0.88 (0.79, 0.98) and 0.91 (0.86, 0.96) for T2D and hypertension, respectively (P-trend < 0.0001). Associations were stronger for the Palaeolithic-like lifestyle score; in the fully adjusted model, a 1-SD increase of the score was associated with 19% and 6% lower risks of T2D and hypertension, respectively. Risks lowered successively with each increase in quintile; those in the highest versus the lowest quintile had HR (95% CI) of 0.58 (0.52, 0.65) and 0.85 (0.80, 0.90) for T2D and hypertension, respectively (P-trend < 0.0001).

CONCLUSIONS

Our data suggest that adhering to a PD based on fruit, vegetables, lean meats, fish, and nuts, and incorporating a Palaeolithic-like lifestyle could be promising options to prevent T2D and hypertension.

Paleolithic Diet-Effect on the Health Status and Performance of Athletes?

The aim of this meta-analysis was to review the impact of a Paleolithic diet (PD) on selected health indicators (body composition, lipid profile, blood pressure, and carbohydrate metabolism) in the short and long term of nutrition intervention in healthy and unhealthy adults. A systematic review of randomized controlled trials of 21 full-text original human studies was conducted. Both the PD and a variety of healthy diets (control diets (CDs)) caused reduction in anthropometric parameters, both in the short and long term. For many indicators, such as weight (body mass (BM)), body mass index (BMI), and waist circumference (WC), impact was stronger and especially found in the short term. All diets caused a decrease in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG), albeit the impact of PD was stronger. Among long-term studies, only PD cased a decline in TC and LDL-C. Impact on blood pressure was observed mainly in the short term. PD caused a decrease in fasting plasma (fP) glucose, fP insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) and glycated hemoglobin (HbA1c) in the short run, contrary to CD. In the long term, only PD caused a decrease in fP glucose and fP insulin. Lower positive impact of PD on performance was observed in the group without exercise. Positive effects of the PD on health and the lack of experiments among professional athletes require longer-term interventions to determine the effect of the Paleo diet on athletic performance.

Using a Paleo Ratio to Assess Adherence to Paleolithic Dietary Recommendations in a Randomized Controlled Trial of Individuals with Type 2 Diabetes

This study is a secondary analysis of a randomized controlled trial using Paleolithic diet and exercise in individuals with type 2 diabetes. We hypothesized that increased adherence to the Paleolithic diet was associated with greater effects on blood pressure, blood lipids and HbA1c independent of weight loss. Participants were asked to follow a Paleolithic diet for 12 weeks and were randomized to supervised exercise or general exercise recommendations. Four-day food records were analyzed, and food items characterized as "Paleolithic" or "not Paleolithic". Foods considered Paleolithic were lean meat, poultry, fish, seafood, fruits, nuts, berries, seeds, vegetables, and water to drink; "not Paleolithic" were legumes, cereals, sugar, salt, processed foods, and dairy products. A Paleo ratio was calculated by dividing the Paleolithic calorie intake by total calorie intake. A multiple regression model predicted the outcome at 12 weeks using the Paleo ratio, group affiliation, and outcome at baseline as predictors. The Paleo ratio increased from 28% at baseline to 94% after the intervention. A higher Paleo ratio was associated with lower fat mass, BMI, waist circumference, systolic blood pressure, and serum triglycerides at 12 weeks, but not with lower HbA1c levels. The Paleo ratio predicted triglyceride levels independent of weight loss (p = 0.046). Moreover, an increased monounsaturated/saturated fatty acids ratio and an increased polyunsaturated/saturated fatty acids ratio was associated with lower triglyceride levels independent of weight loss. (p = 0.017 and p = 0.019 respectively). We conclude that a higher degree of adherence to the Paleolithic diet recommendations improved fat quality and was associated with improved triglyceride levels independent of weight loss among individuals with type 2 diabetes.

An evolutionary mismatch narrative to improve lifestyle medicine: a patient education hypothesis

An evolutionary perspective provides a unifying explanation for the modifiable risk factors and lifestyle-based interventions for the leading causes of morbidity and mortality globally. Non-communicable diseases develop from an evolutionary mismatch between the prior environment and modern patterns of behavior; however, it is unclear whether an evolutionary mismatch narrative could promote positive behavior change in patients. We hypothesize that educating patients about evolutionary mismatch could augment efforts to improve healthful behavior. Specifically, explaining the 'why' behind what is being recommended could promote health literacy and adherence. Furthermore, we offer suggestions of how clinicians could educate patients about evolutionary mismatch for key-lifestyle factors, diet and physical activity, as well as several specific modern diseases. We also consider how to sidestep patients' skepticism of evolutionary theory. Here, we lay the groundwork for research on how educating patients with an evolutionary mismatch narrative could impact health behaviors and improve outcomes.

The effect of paleolithic diet on glucose metabolism and lipid profile among patients with metabolic disorders: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Several randomized clinical trials (RCTs) have investigated the effects of the Paleolithic diet (PD) in adult patients suffering from metabolic disorders. However, the results of these RCTs are conflicting. Therefore, we conducted a systematic review and meta-analysis to assess the effects of the PD in patients with metabolic disorders.

METHODS

We searched the PubMed/Medline, Scopus, Cochrane Databases, Google Scholar, Web of Science, and Embase databases up to June, 2020. The data were pooled using a random-effects model. From the eligible publications, 10 articles were selected for inclusion in this systematic review and meta-analysis. The meta-analysis was performed using a random-effects model. The heterogeneity was determined using the I² statistics and the Cochrane Q test.

RESULTS

The pooled results from the random-effects model showed a significant reduction of the homeostatic model assessment of insulin resistance (HOMA-IR) (weighted mean difference, WMD: -0.39, 95% CI: -0.70, -0.08), fasting insulin (WMD: -12.17 μU/mL, 95% CI: -24.26, -0.08), total cholesterol (WMD: -0.32 mmol/l, 95% CI: -0.49, -0.15), triglycerides (WMD: -0.29 mmol/L, 95% CI: -0.42, -0.16), low-density lipoprotein cholesterol (WMD: -0.35 mmol/L, 95% CI: -0.67, -0.03), blood pressure (BP)(WMD - 5.89 mmHg; 95% CI - 9.973 to - 1.86 for the systolic BP and WMD - 4.01 mmHg; 95% CI - 6.21 to - 1.80 for the diastolic BP values) and C-reactive protein (CRP) levels (WMD: -0.84, mg/L, 95% CI: -1.62, -0.06) in the PD group versus control group.

CONCLUSIONS

Our findings provide better insights into the effect of the PD on the modulation of the glucose and lipid metabolism factors in patients with metabolic disorders, providing comprehensive information for the development of future RCTs with a high quality design.

Current Evidence Regarding Low-carb Diets for The Metabolic Control of Type-2 Diabetes

The management of diabetes requires a medical nutrition therapy as an essential part of this treatment. There should be no "one-size-fits-all" eating pattern for different patient´s profiles with diabetes. It is clinically complex to suggest an ideal percentage of calories from carbohydrates, protein and lipids recommended for all patients with diabetes. Among the eating patterns that have shown beneficial effects on metabolic control of patients with type 2 diabetes is the lowcarb diet, since the carbohydrate ingestion is viewed as the most important determinant of postprandial glucose and insulin response. In this context, theoretically, it could make sense to reduce the daily amount of carbohydrates ingested, to achieve lower levels of HbA1c. There could be risks associated to this approach. The adherence to a low-carb diet is here also discussed. This narrative review shows on the current evidence for answering these questions regarding low-carb diet as a possible alternative eating pattern for type 2 diabetes.

Healthy Diet: New Rations for Individual Use

Nutrition is one of the most significant factors influencing the state of health, the development of diseases and the generally the human longevity. The nature of nutrition, which has a protective effect, is the basis of the healthy diet. Among healthy nutritious rations, there are those that have developed naturally, formed from the cultural food heritage and later were made in scientific nutritional recommendations. These are such diets as the Mediterranean type of food, the Scandinavian diet, the Tibetan style of food, etc. At the same time, there are diets specially developed by specialists for specific purposes. All of them correspond to the basic principles of the healthy diet: balance, usefulness and energy balance. This article offers an overview of the use of individual diets that have been developed by nutritionists, such as the intermittent fasting diet, the Paleo diet, and the DASH (Dietary Approaches to Stop Hypertension) diet. The article discusses the differences and advantages of these dietary approaches, presents the results of effectiveness, considers the limitations and features of their use.

Hamiltonian patterns of age-dependent adaptation to novel environments

Our intuitive understanding of adaptation by natural selection is dominated by the power of selection at early ages in large populations. Yet, as the forces of natural selection fall with adult age, we expect adaptation to be attenuated with age. Explicit simulations of age-dependent adaptation suggest that populations adapt to a novel environment quickly at early ages, but only slowly and incompletely at later adult ages. Experimental tests for age-dependent adaptation to a novel diet were performed on populations of Drosophila melanogaster. The results support the prediction that populations should perform better on an ancestral, long-abandoned diet, compared to an evolutionarily recent diet, only at later ages. D. melanogaster populations also perform poorly on a novel diet compared to an evolutionarily recent diet that has been sustained for hundreds of generations, particularly at earlier ages. Additional experiments demonstrate that the timing of the shift to better performance in our populations on the long-abandoned diet is dependent on when the forces of natural selection weaken in the evolutionary history of experimental populations. Taken together, these experimental findings suggest that the forces of natural selection scale the rate of adaptation to novel environments.

Scoping review of Paleolithic dietary patterns: a definition proposal

The Paleolithic diet (PaleoDiet) is an allegedly healthy dietary pattern inspired by the consumption of wild foods and animals assumed to be consumed in the Paleolithic era. Despite gaining popularity in the media, different operational definitions of this Paleolithic nutritional intake have been used in research. Our hypothesis is that specific components used to define the PaleoDiet may modulate the association of this diet with several health outcomes. We comprehensively reviewed currently applied PaleoDiet scores and suggested a new score based on the food composition of current PaleoDiet definitions and the theoretical food content of a staple dietary pattern in the Paleolithic age. In a PubMed search up to December 2019, fourteen different PaleoDiet definitions were found. We observed some common components of the PaleoDiet among these definitions although we also found high heterogeneity in the list of specific foods that should be encouraged or banned within the PaleoDiet. Most studies suggest that the PaleoDiet may have beneficial effects in the prevention of cardiometabolic diseases (type 2 diabetes, overweight/obesity, CVD and hyperlipidaemias) but the level of evidence is still weak because of the limited number of studies with a large sample size, hard outcomes instead of surrogate outcomes and long-term follow-up. Finally, we propose a new PaleoDiet score composed of eleven food items, based on a high consumption of fruits, nuts, vegetables, fish, eggs and unprocessed meats (lean meats); and a minimum content of dairy products, grains and cereals, and legumes and practical absence of processed (or ultra-processed) foods or culinary ingredients.

The evolution of the heart-healthy diet for vascular health: A walk through time

The rate of cardiovascular disease (CVD) mortality reduction in the United States has plateaued recently, despite the development of novel preventive pharmacotherapies, increased access to care, and healthcare spending. This is largely due to American's poor dietary patterns and practices causing increasing trends in the prevalence of obesity and type 2 diabetes mellitus. For decades, dietary guidelines on 'healthy diets' to reduce CVD risk, grounded in epidemiological research, have been nationally distributed to Americans. In this review, we highlight landmark events in modern nutrition science and how these have framed past and current understandings of diet and health. We also follow the evolution of dietary recommendations for Americans throughout the years, with an emphasis on recommendations aimed to reduce risk for CVD and mortality. Secondly, we examine how the low-fat ideology came to dominate America in the last decades of the 20th century and subsequently contributed to an excess intake of refined carbohydrates which, in the context of an increasingly sedentary lifestyle, may have fueled the obesity epidemic. We then examine the current major evidence-based dietary patterns and specific dietary approaches to reduce CVD risk, reviewing the literature surrounding nutritional components of the heart-healthy diet and discussing the dietary patterns proven most effective for CVD prevention: the Dietary Approaches to Stop Hypertension (DASH) diet, the Mediterranean diet, and the healthy vegetarian diet. Finally, we discuss emerging dietary trends, considerations for nutrition counseling, and future directions within the important field of nutrition, with the ultimate goal of improving vascular health.

The Effect of the Paleolithic Diet vs. Healthy Diets on Glucose and Insulin Homeostasis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Recently, the Paleolithic diet became popular due to its possible health benefits. Several, albeit not all, studies suggested that the consumption of the Paleolithic diet might improve glucose tolerance, decrease insulin secretion, and increase insulin sensitivity. Therefore, the aim of this meta-analysis was to compare the effect of the Paleolithic diet with other types of diets on glucose and insulin homeostasis in subjects with altered glucose metabolism. Four databases (PubMed, Web of Sciences, Scopus, and the Cochrane Library) were searched to select studies in which the effects of the Paleolithic diet on fasting glucose and insulin levels, glycated hemoglobin (HbA1c), homeostasis model assessment of insulin resistance (HOMA-IR), and area under the curve (AUC 0–120) for glucose and insulin during the oral glucose tolerance test were assessed. In total, four studies with 98 subjects which compared the effect of the Paleolithic diet with other types of diets (the Mediterranean diet, diabetes diet, and a diet recommended by the Dutch Health Council) were included in this meta-analysis. The Paleolithic diet did not differ from other types of diets with regard to its effect on fasting glucose (standardized mean difference (SMD): −0.343, 95% confidence interval (CI): −0.867, 0.181, p = 0.200) and insulin (SMD: −0.141; 95% CI: −0.599, 0.318; p = 0.548) levels. In addition, there were no differences between the Paleolithic diet and other types of diets in HOMA-IR (SMD: −0.151; 95% CI: −0.610, 0.309; p = 0.521), HbA1c (SMD: −0.380; 95% CI: −0.870, 0.110; p = 0.129), AUC 0–120 glucose (SMD: −0.558; 95% CI: −1.380, 0.264; p = 0.183), and AUC 0–120 insulin (SMD: −0.068; 95% CI: −0.526, 0.390; p = 0.772). In conclusion, the Paleolithic diet did not differ from other types of diets commonly perceived as healthy with regard to effects on glucose and insulin homeostasis in subjects with altered glucose metabolism.

The effects of the Paleolithic Diet on obesity anthropometric measurements

Abstract Comparing the effects of Paleolithic Diet (PD) and of a Guidelines Substantiated Diet (GSD) on anthropometric indicators of obese individuals. Randomized clinical trial. Obese patients were divided into two groups based on dietary prescription: PD and GSD. These diets encompassed 82 and 73 patients, respectively, who were followed-up for 60 days. Anthropometric measurements were taken before the beginning of the trial, at the 30th day of it and at the end of the experimental period. At the 60th experimental day, there was 26.8% treatment abandonment by individuals in group PD and 19.2% by the ones in group GSD; there was not difference between groups (p = 0.684). Weight and height measurements were taken in order to determine body mass index (BMI), waist circumference (WC) and hip circumference (HC), which allowed determining the waist/hip ratio (WHR). There was no initial difference between groups in demographic, socioeconomic, exercising and anthropometric variables (p > 0.05). Group PD recorded the highest weight (p = 0.003), BMI (p = 0.002) and WC (p = 0.033) values at the 30th experimental day. Group PD kept the highest weight loss at the 60th day (p < 0,001), as well as the highest BMI (p < 0.001), WC (p = 0.002) and WHR (p = 0.002) reduction. PD is a feasible option to treat obesity, it led to reduced anthropometric markers. Other studies are necessary to assure the safety of its use for longer periods of time.

Spiritually motivated restrictions on animal products have a limited impact on consumption of healthy plant-based foods

Plant-based diets are considered healthier than many omnivorous diets. However, it is unclear that restriction of animal products necessarily motivates increased consumption of nutrient- and fibre-rich plant-based foods as opposed to energy-dense but nutrient-poor plant-based foods containing refined grains and added sugars and fats. The present study examined FFQ and food record data from ninety-nine individuals in the USA with varying degrees of adherence to the Orthodox Christian tradition of restricting meat, dairy and egg (MDE) products for 48 d prior to Easter to investigate whether restricting MDE products in the absence of explicit nutritional guidance would lead to increased consumption of healthy plant-based foods and greater likelihood of meeting dietary recommendations. Multiple linear regression models assessed changes in major food groups, energy and nutrients in relation to the degree of reduction in MDE consumption. Logistic regression analyses tested the odds of meeting 2015-2020 Dietary Guidelines for Americans on plant-based foods in relation to MDE restriction. Each serving reduction in MDE products was associated with small (approximately 0·1-0·7 serving) increases in legumes, soya products and nuts/seeds (all P values < 0·005). MDE restriction was not associated with higher odds of meeting recommendations on vegetable, fruit or whole-grain intake. Consumption of refined grains and added sugars did not change in relation to MDE restriction but remained above recommended thresholds, on average. These findings demonstrate that a reduction of MDE products for spiritual purposes may result in increases in some nutrient-rich plant-based foods but may not uniformly lead to a healthier dietary composition.

Diet Quality and Cardiovascular Disease Risk in Postmenopausal Women With Type 2 Diabetes Mellitus: The Women's Health Initiative

Background

Dietary patterns are associated with cardiovascular disease (CVD) risk in the general population, but diet–CVD association in populations with diabetes mellitus is limited. Our objective was to examine the association between diet quality and CVD risk in a population with type 2 diabetes mellitus.

Methods and Results

We analyzed prospective data from 5809 women with prevalent type 2 diabetes mellitus at baseline from the Women's Health Initiative. Diet quality was defined using alternate Mediterranean, Dietary Approach to Stop Hypertension, Paleolithic, and American Diabetes Association dietary pattern scores calculated from a validated food frequency questionnaire. Multivariable Cox's proportional hazard regression was used to analyze the risk of incident CVD. During mean 12.4 years of follow‐up, 1454 (25%) incident CVD cases were documented. Women with higher alternate Mediterranean, Dietary Approach to Stop Hypertension, and American Diabetes Association dietary pattern scores had a lower risk of CVD compared with women with lower scores (Q5 v Q1) (hazard ratio [HR]_aMed 0.77, 95% CI 0.65–0.93; HR_DASH 0.69, 95% CI 0.58–0.83; HR_ADA 0.71, 95% CI 0.59–0.86). No association was observed between the Paleolithic score and CVD risk.

Conclusions

Dietary patterns that emphasize higher intake of fruits, vegetables, whole grains, nuts/seeds, legumes, a high unsaturated:saturated fat ratio, and lower intake of red and processed meats, added sugars, and sodium are associated with lower CVD risk in postmenopausal women with type 2 diabetes mellitus.

Paleolithic diet during pregnancy-A potential beneficial effect on metabolic indices and birth weight

BACKGROUND

Paleolithic diet has recently gained popularity due to its presumed health benefits. The favorable metabolic effects of this diet were assessed in non-pregnant population but its impact during pregnancy remains to be evaluated.

STUDY DESIGN

A retrospective cohort study comparing two groups. Group A comprised of women with singleton low-risk pregnancy adherent to paleolithic diet throughout gestation (n = 37). Group B comprised low risk pregnant women on a regular diet (n = 39). Women were excluded if they had low adherence to diet, started paleolithic diet during pregnancy, and had pre-gestational diabetes mellitus or other types of metabolic syndrome such as pre gestational hyperlipidemia, hypertension or BMI > 35. Blood indices such as Glucose challenge test scores, hemoglobin, ferritin, and TSH levels were compared. Other pregnancy factors such as maternal weight gain, rest days during gestation and pregnancy complications such as IUGR, GDM or preeclampsia were compared. Lastly, obstetrical outcomes such as mode of delivery and complications such as high-grade tears, as well as neonatal factors such as birth weight and pH were compared between the two groups.

RESULTS

General maternal characteristics such as age, BMI and parity were comparable between the two groups. Women who maintained a paleolithic diet had a significant decrease in glucose challenge test scores (95.8 mg/dL vs. 123.1 mg/dL, p < 0.01) and increase in hemoglobin levels (12.1 g/dL vs. 11.05 g/dL p < 0.01) and Ferritin (32.1 vs 21.3 mg/mL, p = 0.03) compared to women maintaining regular diet. Maternal pregnancy weight gain was also slightly decreased in group A (9.3Kg vs. 10.8 kg, p = 0.03). Birthweights were lower in group A (3098 g Vs.3275 g, p = 0.046) with no difference in adverse neonatal outcomes. We found no differences in other pregnancy complications or labor outcomes such as mode of delivery, shoulder dystocia or high grade perineal tears.

CONCLUSION

Paleolithic diet maintained during pregnancy may have a beneficial effect on the glucose tolerance. It also may increase iron stores and hemoglobin levels. Neonates of women maintaining paleolithic diet are slightly lighter but appropriate for gestational age with no difference in neonatal outcomes.

Gut microbiome response to a modern Paleolithic diet in a Western lifestyle context

The modern Paleolithic diet (MPD), featured by the consumption of vegetables, fruit, nuts, seeds, eggs, fish and lean meat, while excluding grains, dairy products, salt and refined sugar, has gained substantial public attention in recent years because of its potential multiple health benefits. However, to date little is known about the actual impact of this dietary pattern on the gut microbiome (GM) and its implications for human health. In the current scenario where Western diets, low in fiber while rich in industrialized and processed foods, are considered one of the leading causes of maladaptive GM changes along human evolution, likely contributing to the increasing incidence of chronic non-communicable diseases, we hypothesize that the MPD could modulate the Western GM towards a more “ancestral” configuration. In an attempt to shed light on this, here we profiled the GM structure of urban Italian subjects adhering to the MPD, and compared data with other urban Italians following a Mediterranean Diet (MD), as well as worldwide traditional hunter-gatherer populations from previous publications. Notwithstanding a strong geography effect on the GM structure, our results show an unexpectedly high degree of biodiversity in MPD subjects, which well approximates that of traditional populations. The GM of MPD individuals also shows some peculiarities, including a high relative abundance of bile-tolerant and fat-loving microorganisms. The consumption of plant-based foods–albeit with the exclusion of grains and pulses–along with the minimization of the intake of processed foods, both hallmarks of the MPD, could therefore contribute to partially rewild the GM but caution should be taken in adhering to this dietary pattern in the long term.

Fad Diets: Hype or Hope?

PURPOSE OF REVIEW

Obesity continues to be a growing concern globally due to association with a number of comorbidities and contributing significantly to increase in health care expenditures. Despite availability of a number of treatment modalities, lifestyle modification with dietary modification and exercise continues to be the foundation. However, the standard model of lifestyle modification is not efficacious or sustainable for many patients leading them to seek alternative approaches. We conducted a comprehensive literature review to present the data regarding efficacy and sustainability of many common dietary approaches.

RECENT FINDINGS

Building upon previous work, recent randomized controlled trials have compared many popular diets head to head in varying patient populations. Along with the weight changes, studies have investigated the changes in metabolic parameters, inflammatory markers, and cardiac risk factor reduction. Though the studies do not show superiority of one diet compared to the other, the preventive benefits and other favorable metabolic changes of the diets make them worthy of consideration.

Influence of Paleolithic diet on anthropometric markers in chronic diseases: systematic review and meta-analysis

BACKGROUND

The Paleolithic diet has been studied in the scope of prevention and control of chronic noncommunicable diseases (CNCD). The objective of this study was to analyze the influence of the Paleolithic diet on the prevention and control of CNCD in humans, specifically on anthropometric markers, through a systematic review with meta-analysis.

METHODS

What is the effect of the Paleolithic diet on anthropometric parameters (weight, body mass index and waist circumference) compared to other control diets based on recommendations in adults? We included only randomized studies with humans that used the Paleolithic Diet in the prevention and control of CNCD published in Portuguese, English or Spanish. The search period was until March 2019, in the LILACS, PubMed, Scielo, Science Direct, Medline, Web of Science and Scopus databases. The abstracts were evaluated by two researchers. We found 1224 articles, of which 24 were selected and 11 were included in the meta-analysis. The effect of dietary use on body weight, body mass index and waist circumference was evaluated.

RESULTS

The summary of the effect showed a loss of - 3.52 kg in the mean weight (CI 95%: - 5.26; - 1.79; p < 0,001; I² = 24%) of people who adopted the Paleolithic diet compared to diets based on recommendations. The analysis showed a positive association of adopting the Paleolithic diet in relation to weight loss. The effect was significant on weight, body mass index and waist circumference.

CONCLUSION

The Paleolithic diet may assist in controlling weight and waist circumference and in the management of chronic diseases. However, more randomized clinical studies with larger populations and duration are necessary to prove health benefits.

TRIAL REGISTRATION

CRD42015027849 .

Effects of a Paleolithic Diet on Cardiovascular Disease Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

There is some evidence supporting the beneficial effects of a Paleolithic Diet (PD) on cardiovascular disease risk factors. This diet advises consuming lean meat, fish, vegetables, fruits, and nuts and avoiding intake of grains, dairy products, processed foods, and added sugar and salt. This study was performed to assess the effects of a PD on cardiovascular disease risk factors including anthropometric indexes, lipid profile, blood pressure, and inflammatory markers using data from randomized controlled trials. A comprehensive search was performed in the PubMed, Scopus, ISI Web of Science, and Google Scholar databases up to August, 2018. A meta-analysis was performed using a random-effects model to estimate the pooled effect size. Meta-analysis of 8 eligible studies revealed that a PD significantly reduced body weight [weighted mean difference (WMD) = -2.17 kg; 95% CI: -3.48, -0.87 kg], waist circumference (WMD = -2.90 cm; 95% CI: -4.51, -1.28 cm), body mass index (in kg/m2) (WMD = -1.15; 95% CI: -1.68, -0.62), body fat percentage (WMD = -1.38%; 95% CI: -2.08%, -0.67%), systolic (WMD = -4.24 mm Hg; 95% CI: -7.11, -1.38 mm Hg) and diastolic (WMD = -2.95 mm Hg; 95% CI: -4.72, -1.18 mm Hg) blood pressure, and circulating concentrations of total cholesterol (WMD = -0.22 mg/dL; 95% CI: -0.42, -0.03 mg/dL), TGs (WMD = -0.23 mg/dL; 95% CI: -0.46, -0.01 mg/dL), LDL cholesterol (WMD = -0.13 mg/dL; 95% CI: -0.25, -0.01 mg/dL), and C-reactive protein (CRP) (WMD = -0.41 mg/L; 95% CI: -0.81, -0.008 mg/L) and also significantly increased HDL cholesterol (WMD = 0.05 mg/dL; 95% CI: 0.005, 0.10 mg/dL). However, sensitivity analysis revealed that the overall effects of a PD on lipid profile, blood pressure, and circulating CRP concentrations were significantly influenced by removing some studies, hence the results must be interpreted with caution. Although the present meta-analysis revealed that a PD has favorable effects on cardiovascular disease risk factors, the evidence is not conclusive and more well-designed trials are still needed.

Postprandial levels of GLP-1, GIP and glucagon after 2 years of weight loss with a Paleolithic diet: a randomised controlled trial in healthy obese women

Objective To investigate how weight loss by different diets impacts postprandial levels of glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon. Methods In this single-centre, parallel group 2-year trial, 70 healthy postmenopausal obese women were randomised to the Paleolithic diet or a healthy control diet based on Nordic Nutrition Recommendations. Both diets were without calorie restriction. The primary outcome was the change in fat mass. Here, secondary analyses on GLP-1, GIP and glucagon measured during an OGTT are described. Results In the Paleolithic diet group, mean weight loss compared to baseline was 11% at 6 months and 10% at 24 months. In the control diet group, mean weight loss was 6% after 6 and 24 months (P = 0.0001 and P = 0.049 for the comparison between groups at 6 and 24 months respectively). Compared to baseline, the mean incremental area under the curve (iAUC) for GLP-1 increased by 34 and 45% after 6 and 24 months in the Paleolithic diet group and increased by 59% after 24 months in the control diet group. The mean iAUC for GIP increased only in the Paleolithic diet group. The area under the curve (AUC) for glucagon increased during the first 6 months in both groups. The fasting glucagon increase correlated with the β-hydroxybutyrate increase. Conclusions Weight loss caused an increase in postprandial GLP-1 levels and a further rise occurred during weight maintenance. Postprandial GIP levels increased only after the Paleolithic diet. Reduced postprandial glucagon suppression may be caused by a catabolic state.

Mediterranean-style diet for the primary and secondary prevention of cardiovascular disease

BACKGROUND

The Seven Countries study in the 1960s showed that populations in the Mediterranean region experienced lower coronary heart disease (CHD) mortality probably as a result of different dietary patterns. Later observational studies have confirmed the benefits of adherence to a Mediterranean dietary pattern on cardiovascular disease (CVD) risk factors but clinical trial evidence is more limited.

OBJECTIVES

To determine the effectiveness of a Mediterranean-style diet for the primary and secondary prevention of CVD.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 9); MEDLINE (Ovid, 1946 to 25 September 2018); Embase (Ovid, 1980 to 2018 week 39); Web of Science Core Collection (Thomson Reuters, 1900 to 26 September 2018); DARE Issue 2 of 4, 2015 (Cochrane Library); HTA Issue 4 of 4, 2016 (Cochrane Library); NHS EED Issue 2 of 4, 2015 (Cochrane Library). We searched trial registers and applied no language restrictions.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) in healthy adults and adults at high risk of CVD (primary prevention) and those with established CVD (secondary prevention). Both of the following key components were required to reach our definition of a Mediterranean-style diet: high monounsaturated/saturated fat ratio (use of olive oil as main cooking ingredient and/or consumption of other traditional foods high in monounsaturated fats such as tree nuts) and a high intake of plant-based foods, including fruits, vegetables and legumes. Additional components included: low to moderate red wine consumption; high consumption of whole grains and cereals; low consumption of meat and meat products and increased consumption of fish; moderate consumption of milk and dairy products. The intervention could be dietary advice, provision of relevant foods, or both. The comparison group received either no intervention, minimal intervention, usual care or another dietary intervention. Outcomes included clinical events and CVD risk factors. We included only studies with follow-up periods of three months or more defined as the intervention period plus post intervention follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data and assessed risk of bias. We conducted four main comparisons:1. Mediterranean dietary intervention versus no intervention or minimal intervention for primary prevention;2. Mediterranean dietary intervention versus another dietary intervention for primary prevention;3. Mediterranean dietary intervention versus usual care for secondary prevention;4. Mediterranean dietary intervention versus another dietary intervention for secondary prevention.

MAIN RESULTS

In this substantive review update, 30 RCTs (49 papers) (12,461 participants randomised) and seven ongoing trials met our inclusion criteria. The majority of trials contributed to primary prevention: comparisons 1 (nine trials) and 2 (13 trials). Secondary prevention trials were included for comparison 3 (two trials) and comparison 4 (four trials plus an additional two trials that were excluded from the main analyses due to published concerns regarding the reliability of the data).Two trials reported on adverse events where these were absent or minor (low- to moderate-quality evidence). No trials reported on costs or health-related quality of life.Primary preventionThe included studies for comparison 1 did not report on clinical endpoints (CVD mortality, total mortality or non-fatal endpoints such as myocardial infarction or stroke). The PREDIMED trial (included in comparison 2) was retracted and re-analysed following concerns regarding randomisation at two of 11 sites. Low-quality evidence shows little or no effect of the PREDIMED (7747 randomised) intervention (advice to follow a Mediterranean diet plus supplemental extra-virgin olive oil or tree nuts) compared to a low-fat diet on CVD mortality (hazard ratio (HR) 0.81, 95% confidence interval (CI) 0.50 to 1.32) or total mortality (HR 1.0, 95% CI 0.81 to 1.24) over 4.8 years. There was, however, a reduction in the number of strokes with the PREDIMED intervention (HR 0.60, 95% CI 0.45 to 0.80), a decrease from 24/1000 to 14/1000 (95% CI 11 to 19), moderate-quality evidence). For CVD risk factors for comparison 1 there was low-quality evidence for a possible small reduction in total cholesterol (-0.16 mmol/L, 95% CI -0.32 to 0.00) and moderate-quality evidence for a reduction in systolic (-2.99 mmHg (95% CI -3.45 to -2.53) and diastolic blood pressure (-2.0 mmHg, 95% CI -2.29 to -1.71), with low or very low-quality evidence of little or no effect on LDL or HDL cholesterol or triglycerides. For comparison 2 there was moderate-quality evidence of a possible small reduction in LDL cholesterol (-0.15 mmol/L, 95% CI -0.27 to -0.02) and triglycerides (-0.09 mmol/L, 95% CI -0.16 to -0.01) with moderate or low-quality evidence of little or no effect on total or HDL cholesterol or blood pressure.Secondary preventionFor secondary prevention, the Lyon Diet Heart Study (comparison 3) examined the effect of advice to follow a Mediterranean diet and supplemental canola margarine compared to usual care in 605 CHD patients over 46 months and there was low-quality evidence of a reduction in adjusted estimates for CVD mortality (HR 0.35, 95% CI 0.15 to 0.82) and total mortality (HR 0.44, 95% CI 0.21 to 0.92) with the intervention. Only one small trial (101 participants) provided unadjusted estimates for composite clinical endpoints for comparison 4 (very low-quality evidence of uncertain effect). For comparison 3 there was low-quality evidence of little or no effect of a Mediterranean-style diet on lipid levels and very low-quality evidence for blood pressure. Similarly, for comparison 4 where only two trials contributed to the analyses there was low or very low-quality evidence of little or no effect of the intervention on lipid levels or blood pressure.

AUTHORS' CONCLUSIONS

Despite the relatively large number of studies included in this review, there is still some uncertainty regarding the effects of a Mediterranean-style diet on clinical endpoints and CVD risk factors for both primary and secondary prevention. The quality of evidence for the modest benefits on CVD risk factors in primary prevention is low or moderate, with a small number of studies reporting minimal harms. There is a paucity of evidence for secondary prevention. The ongoing studies may provide more certainty in the future.

Review of Two Popular Eating Plans within the Multiple Sclerosis Community: Low Saturated Fat and Modified Paleolithic

The precise etiology of multiple sclerosis (MS) is unknown but epidemiologic evidence suggests this immune-mediated, neurodegenerative condition is the result of a complex interaction between genes and lifetime environmental exposures. Diet choices are modifiable environmental factors that may influence MS disease activity. Two diets promoted for MS, low saturated fat Swank and modified Paleolithic Wahls Elimination (WahlsElim), are currently being investigated for their effect on MS-related fatigue and quality of life (NCT02914964). Dr. Swank theorized restriction of saturated fat would reduce vascular dysfunction in the central nervous system (CNS). Dr. Wahls initially theorized that detailed guidance to increase intake of specific foodstuffs would facilitate increased intake of nutrients key to neuronal health (Wahls™ diet). Dr. Wahls further theorized restriction of lectins would reduce intestinal permeability and CNS inflammation (WahlsElim version). The purpose of this paper is to review the published research of the low saturated fat (Swank) and the modified Paleolithic (Wahls™) diets and the rationale for the structure of the Swank diet and low lectin version of the Wahls™ diet (WahlsElim) being investigated in the clinical trial.

Combating insulin resistance with the paleo diet

Lifestyle changes that include adopting a healthy diet, such as the paleo diet, can help prevent prediabetes and T2DM. This article explores the potential benefits of replacing low-calorie diets with the paleo diet. As primary care providers, NPs are positioned to help inform patients, particularly those with prediabetes and T2DM, about healthy lifestyle choices and provide them with resources to achieve weight loss success.

How Western Diet And Lifestyle Drive The Pandemic Of Obesity And Civilization Diseases

Westernized populations are plagued by a plethora of chronic non-infectious degenerative diseases, termed as "civilization diseases", like obesity, diabetes, cardiovascular diseases, cancer, autoimmune diseases, Alzheimer's disease and many more, diseases which are rare or virtually absent in hunter-gatherers and other non-westernized populations. There is a growing awareness that the cause of this amazing discrepancy lies in the profound changes in diet and lifestyle during recent human history. This paper shows that the transition from Paleolithic nutrition to Western diets, along with lack of corresponding genetic adaptations, cause significant distortions of the fine-tuned metabolism that has evolved over millions of years of human evolution in adaptation to Paleolithic diets. With the increasing spread of Western diet and lifestyle worldwide, overweight and civilization diseases are also rapidly increasing in developing countries. It is suggested that the diet-related key changes in the developmental process include an increased production of reactive oxygen species and oxidative stress, development of hyperinsulinemia and insulin resistance, low-grade inflammation and an abnormal activation of the sympathetic nervous system and the renin-angiotensin system, all of which play pivotal roles in the development of diseases of civilization. In addition, diet-related epigenetic changes and fetal programming play an important role. The suggested pathomechanism is also able to explain the well-known but not completely understood close relationship between obesity and the wide range of comorbidities, like type 2 diabetes mellitus, cardiovascular disease, etc., as diseases of the same etiopathology. Changing our lifestyle in accordance with our genetic makeup, including diet and physical activity, may help prevent or limit the development of these diseases.

Associations of evolutionary-concordance diet, Mediterranean diet and evolutionary-concordance lifestyle pattern scores with all-cause and cause-specific mortality

Various individual diet and lifestyle factors are associated with mortality. Investigating these factors collectively may help clarify whether dietary and lifestyle patterns contribute to life expectancy. We investigated the association of previously described evolutionary-concordance and Mediterranean diet pattern scores and a novel evolutionary-concordance lifestyle pattern score with all-cause and cause-specific mortality in the prospective Iowa Women's Health Study (1986-2012). We created the diet pattern scores from Willett FFQ responses, and the lifestyle pattern score from self-reported physical activity, BMI and smoking status, and assessed their associations with mortality, using multivariable Cox proportional hazards regression. Of the 35 221 55- to 69-year-old cancer-free women at baseline, 18 687 died during follow-up. The adjusted hazard ratios (HR) and 95 % CI for all-cause, all CVD, and all-cancer mortality among participants in the highest relative to the lowest quintile of the evolutionary-concordance lifestyle score were, respectively, 0·52 (95 % CI 0·50, 0·55), 0·53 (95 % CI 0·49, 0·57) and 0·51 (95 % CI 0·46, 0·57). The corresponding findings for the Mediterranean diet score were HR 0·85 (95 % CI 0·82, 0·90), 0·83 (95 % CI 0·76, 0·90) and 0·93 (95 % CI 0·84, 1·03), and for the evolutionary-concordance diet score they were close to null and not statistically significant. The lowest estimated risk was among those in the highest joint quintile of the lifestyle score and either diet score (both Pinteraction <0·01). Our findings suggest that (1) a more Mediterranean-like diet pattern and (2) a more evolutionary-concordant lifestyle pattern, alone and in interaction with a more evolutionary-concordant or Mediterranean diet pattern, may be inversely associated with mortality.

A Paleolithic diet lowers resistant starch intake but does not affect serum trimethylamine-N-oxide concentrations in healthy women

The Paleolithic diet excludes two major sources of fibre, grains and legumes. However, it is not known whether this results in changes to resistant starch (RS) consumption. Serum trimethylamine-N-oxide (TMAO) is produced mainly from colonic fermentation and hepatic conversion of animal protein and is implicated in CVD, but changes in RS intake may alter concentrations. We aimed to determine whether intake of RS and serum concentrations of TMAO varied in response to either the Paleolithic or the Australian Guide to Healthy Eating (AGHE) diets and whether this was related to changes in food group consumption. A total of thirty-nine women (mean age 47 (sd 13) years, BMI 27 (sd 4) kg/m²) were randomised to AGHE (n 17) or Paleolithic diets (n 22) for 4 weeks. Serum TMAO concentrations were measured using liquid chromatography–MS; food groups, fibre and RS intake were estimated from weighed food records. The change in TMAO concentrations between groups (Paleolithic 3·39 μmv. AGHE 1·19 μm, P = 0·654) did not reach significance despite greater red meat and egg consumption in the Paleolithic group (0·65 serves/d; 95 % CI 0·2, 1·1; P <0·01, and 0·22 serves/d; 95 % CI 0·1, 0·4, P <0·05, respectively). RS intake was significantly lower on the Paleolithic diet (P <0·01) and was not associated with TMAO concentrations. However, the limited data for RS and the small sample size may have influenced these findings. While there were no significant changes in TMAO concentrations, increased meat consumption and reduced RS intake warrant further research to examine the markers of gastrointestinal health of Paleolithic diet followers and to update Australian food databases to include additional fibre components.

A heterogeneous response of liver and skeletal muscle fat to the combination of a Paleolithic diet and exercise in obese individuals with type 2 diabetes: a randomised controlled trial

AIMS/HYPOTHESIS

The aim of the study was to investigate ectopic fat deposition and insulin sensitivity, in a parallel single-blinded randomised controlled trial, comparing Paleolithic diet alone with the combination of Paleolithic diet and exercise in individuals with type 2 diabetes.

METHODS

Thirty-two individuals with type 2 diabetes with BMI 25-40 kg/m² and 30-70 years of age followed a Paleolithic diet ad libitum for 12 weeks. In addition, study participants were randomised by computer program to either supervised combined exercise training (PD-EX group) or standard care exercise recommendations (PD group). Staff performing examinations and assessing outcomes were blinded to group assignment. Thirteen participants were analysed in each group: hepatic and peripheral insulin sensitivity were measured using the hyperinsulinaemic-euglycaemic clamp technique combined with [6,6-²H₂]glucose infusion, and liver fat was assessed by proton magnetic resonance spectroscopy; both analyses were secondary endpoints. Intramyocellular lipid (IMCL) content was measured by magnetic resonance spectroscopy as a secondary analysis. All examinations were performed at Umeå University Hospital, Umeå, Sweden.

RESULTS

Both study groups showed a median body weight loss of 7 kg. Fat mass decreased by 5.7 kg in the PD group and by 6.5 kg in the PD-EX group. Maximum oxygen uptake increased in the PD-EX group only. Liver fat showed a consistent reduction (74% decrease) in the PD group, while the response in the PD-EX group was heterogeneous (p < 0.05 for the difference between groups). IMCL content of the soleus muscle decreased by 40% in the PD group and by 22% in the PD-EX group (p < 0.05 for the difference between groups). Both groups improved their peripheral and adipose tissue insulin sensitivity, but not their hepatic insulin sensitivity. Plasma fetuin-A decreased by 11% in the PD group (p < 0.05) and remained unchanged in the PD-EX group. Liver fat changes during the intervention were correlated with changes in fetuin-A (r_S = 0.63, p < 0.01). Participants did not report any important adverse events caused by the intervention.

CONCLUSIONS/INTERPRETATION

A Paleolithic diet reduced liver fat and IMCL content, while there was a tissue-specific heterogeneous response to added exercise training.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01513798 FUNDING: Swedish Diabetes Research Foundation, County Council of Västerbotten, Swedish Heart and Lung Foundation, King Gustav V and Queen Victoria's Foundation.

Weight outcome after 2 years of a diet that excludes six processed foods: exploratory study of the "1,2,3 diet" in a moderately obese population

BACKGROUND

The Paleolithic diet, a diet devoid of food-processing procedure, seems to produce a greater decrease in weight compared to healthy reference diets but its limited food choices make it difficult to implement in our modern times where refined food is dominant.

OBJECTIVE

To evaluate the effects of a 2-year diet that excludes only six refined foodstuffs implicated in obesity. Professional contact was kept minimal to approximate the approach used by most dieters.

DESIGN

Single-arm, open-label, exploratory study.

SETTING

One academic medical center, outpatient setting.

PATIENTS

One hundred and five subjects with a mean age of 50 (SD, 14 years) and mean body mass index of 30.5 kg/m² (SD, 4 kg/m²). Thirty-nine percent had type 2 diabetes.

INTERVENTION

An ad libitum diet that excludes six refined foodstuffs (margarine, vegetable oils, butter, cream, processed meat, and sugary drinks) called the "1,2,3 diet".

OUTCOMES

Weight at 2 years was the primary outcome. Secondary outcomes included number of patients who lost more than 5% of initial body weight, glycated hemoglobin (HbA_1c) level, and changes in dietary behavior.

RESULTS

Average weight loss was 4.8 kg (p<0.001), representing 5.6% of their initial body weight. Among completers (51%), the average weight loss was 5.5 kg (p<0.001), and 56% had a reduction of at least 5% of their initial body weight. Among diabetics, weight loss was similar to nondiabetics, and mean HbA_1c level decreased by 1% (p=0.001) without modification in glucose-lowering medications. A higher intake of bread, dairy products, chocolate, and fresh fruits was the typical trend in dietary changes reported by completers.

CONCLUSION

In this exploratory study, there was a significant long-term weight loss with the "1,2,3 diet" despite minimal professional contact. Given the lack of a control group and high attrition rate, further evaluation of this diet is warranted.

Central obesity and the Mediterranean diet: A systematic review of intervention trials

Central obesity is associated with chronic low-grade inflammation, and is a risk factor for cardiometabolic syndrome. The Mediterranean diet pattern has a convincing evidence-base for improving cardiometabolic health. This review investigated the impact of Mediterranean diet interventions on central obesity, specifically. A systematic literature search was conducted in the MEDLINE, CINAHL, EMBASE and Cochrane library databases. Search terms included: 'Mediterranean Diet', 'Mediterranean dietary pattern', 'central obesity' and 'visceral fat'. The search was limited to English language and humans ≥18 years. Eighteen articles met the eligibility criteria and reported at least one outcome measure of central obesity with Mediterranean diet intervention. Central obesity measures included waist circumference (16 studies), waist-hip ratio (5 studies) and visceral fat (2 studies). Thirteen (72%) of the studies, totaling 7186 subjects (5168 subjects assigned to a Mediterranean Diet), reported a significant reduction in central obesity with a Mediterranean-type diet. However, seven out of these 13 interventions employed energy restriction, and only three showed a statistically significant favorable effect of the Mediterranean diet relative to a control group. This systematic review highlights the potential for a Mediterranean diet intervention to reduce central obesity and in turn reduce obesity-related chronic disease risk and associated public health burden.

Relationship Between β-cell Response and Insulin Sensitivity in Horses based on the Oral Sugar Test and the Euglycemic Hyperinsulinemic Clamp

Background

A hyperbolic relationship between β‐cell response and insulin sensitivity (IS) has been described in several species including rodents, dogs, and humans. This relationship has not been elucidated in the horse.

Hypothesis/Objectives

To determine whether the hyperbolic relationship between β‐cell response and IS exists in horses by using indices of β‐cell response from the oral sugar test (OST) and IS measurements from the euglycemic hyperinsulinemic clamp (EHC). A second aim was to compare how well IS estimates from the OST and EHC correlate.

Animals

Forty‐nine horses with different degrees of insulin regulation (normal‐to‐severe insulin dysregulation).

Methods

Cross‐sectional study. Horses were examined with an OST and an EHC.

Results

Decreased IS was associated with increased β‐cell response in the horses. Nine of 12 comparisons between indices of β‐cell response and IS measures fulfilled the criteria for a hyperbolic relationship. Indices of IS calculated from the OST correlated highly with the insulin‐dependent glucose disposal rate (M) and the insulin‐dependent glucose disposal rate per unit of insulin (M/I) determined from the EHC (r = 0.81–0.87).

Conclusions and Clinical Importance

A hyperbolic relationship between β‐cell response and IS exists in horses, which suggest that horses with insulin dysregulation respond not only with postprandial hyperinsulinemia but are also insulin resistant. The OST is primarily a test for β‐cell response rather than a test for IS, but calculated indices of IS from the OST may be useful to estimate IS in horses, especially when the horse is insulin resistant.

Attenuated Low-Grade Inflammation Following Long-Term Dietary Intervention in Postmenopausal Women with Obesity

OBJECTIVE

Abdominal fat accumulation after menopause is associated with low-grade inflammation and increased risk of metabolic disorders. Effective long-term lifestyle treatment is therefore needed.

METHODS

Seventy healthy postmenopausal women (age 60 ± 5.6 years) with BMI 32.5 ± 5.5 were randomized to a Paleolithic-type diet (PD) or a prudent control diet (CD) for 24 months. Blood samples and fat biopsies were collected at baseline, 6 months, and 24 months to analyze inflammation-related parameters.

RESULTS

Android fat decreased significantly more in the PD group (P = 0.009) during the first 6 months with weight maintenance at 24 months in both groups. Long-term significant effects (P < 0.001) on adipose gene expression were found for toll-like receptor 4 (decreased at 24 months) and macrophage migration inhibitory factor (increased at 24 months) in both groups. Serum interleukin 6 (IL-6) and tumor necrosis factor α levels were decreased at 24 months in both groups (P < 0.001) with a significant diet-by-time interaction for serum IL-6 (P = 0.022). High-sensitivity C-reactive protein was decreased in the PD group at 24 months (P = 0.001).

CONCLUSIONS

A reduction of abdominal obesity in postmenopausal women is linked to specific changes in inflammation-related adipose gene expression.