Falsehoods and facts about dietary sugars: a call for evidence-based policy

Evaluating the evening carbohydrate dilemma: the effect of within-the-day carbohydrate periodization on body composition and physical fitness

PURPOSE

To assess the effects of carbohydrate timing and type on body composition and physical fitness.

METHODS

Forty-two healthy, trained male volunteers underwent a four-week intervention, randomly divided into three groups: (i) Sleep Low-No Carbohydrates (SL-NCHO): consuming all carbohydrate intake at regular intervals prior to evening training, (ii) Sleep High-Low Glycemic Index (SH-LGI), and (iii) Sleep High-High Glycemic Index (SH-HGI). In both SH-LGI and SH-HGI, carbohydrates were distributed throughout the day, both pre-(60% of total intake) and post-evening training (40% of total intake). The SH-LGI and SH-HGI groups diverged in evening carbohydrate quality, featuring LGI and HGI foods, respectively. All participants performed a standardized exercise program combining resistance exercise and high-intensity interval training. Body composition was assessed using skinfold measurements and bioelectrical impendence analysis. Physical fitness was assessed by measuring VO2max, Visual Reaction Time (VRT), Countermovement Jump (CMJ), and 1-repetition maximum (1RM) in hack squat, chest press, shoulder press, and lat-pulldown exercises.

RESULTS

There was a significant time-effect on both body composition and physical fitness indices. Bodyfat percentage decreased by an average of 1.5% (p < 0.001), fat-mass by 1.4 kg (p < 0.001) and fat-free mass increased by 0.9 kg (p = 0.006). A time-effect was also observed in VO2max, CMJ, 1RM testing, and VRT (all p < 0.05). There were no significant differences among interventions.

CONCLUSIONS

A balanced dietary plan with sufficient nutrient and energy intake promotes body composition optimization and physical fitness, independently of carbohydrate type or timing. This study points towards implementing flexible nutrition interventions, emphasizing the potential of tailored dietary strategies to optimize health and physical fitness.

TRIAL REGISTRATION NUMBER

The trial was registered at clinicaltrials.gov as NCT05464342.

Excess dietary sugar and its impact on periodontal inflammation: a narrative review

INTRODUCTION

Sugar is omnipresent in the current food environment and sugar consumption has drastically risen over the past century. Extensive evidence highlights the negative health consequences of consuming excess dietary sugars, leading the World Health Organization (WHO) and the American Heart Association (AHA) to devise guidelines to restrict sugar intake. According to the WHO's Global Oral Health Status Report of 2022, oral diseases and severe periodontitis are a massive public health problem, and dietary sugars are a modifiable risk factor.

METHODS

We conducted a literature review using key databases to summarise the health effects of excessive sugar consumption and their potential role in periodontal inflammation.

RESULTS AND CONCLUSION

Available evidence suggests that excess dietary fructose and sucrose can cause low-grade systemic inflammation; and induce dysbiosis in both gut and the oral microbiota. Also, dietary sugar is potentially addictive and hypercaloric and its overconsumption can lead to obesity, metabolic syndrome, and other risk factors for periodontal inflammation. Hence, an unbalanced diet with excess dietary sugars holds the potential to initiate and aggravate periodontal inflammation. In the modern food environment that enables and facilitates a high-sugar diet, adopting a diverse diet and restricting sugar intake according to WHO and AHA guidelines seem beneficial to systemic and periodontal health. Since clinical evidence is limited, future research should study the effectiveness of dietary interventions that control sugar consumption in preventing and managing the global public health problem of periodontal inflammation.

The Carbon Isotope Ratio as an Objective Biomarker of Added Sugar Intake: A Scoping Review of Current Evidence in Human Nutrition

Objective biomarkers of dietary intake are needed to advance nutrition research. The carbon isotope ratio (C13/C12; CIR) holds promise as an objective biomarker of added sugar (AS) and sugar-sweetened beverage (SSB) intake. This systematic scoping review presents the current evidence on CIRs from human studies. Search results (through April 12, 2024) yielded 6297 studies and 24 final articles. Studies were observational (n = 12), controlled feeding (n = 10), or dietary interventions (n = 2). CIRs were sampled from blood (n = 23), hair (n = 5), breath (n = 2), and/or adipose tissue (n = 1). Most (n = 17) conducted whole tissue (that is, bulk) analysis, 8 used compound specific isotope analysis (CSIA), and/or 2 studies used methods appropriate for analyzing breath. Studies were conducted in 3 concentrated geographic regions of the United States (n = 7 Virginia; n = 5 Arizona; n = 4 Alaska), with only 2 studies conducted in other countries. Studies that used CSIA to examine the CIR from the amino acid alanine (CIR-Ala; n = 4) and CIR analyzed from breath (n = 2) provided the most robust evidence for CIR as an objective biomarker of AS and SSBs (R2 range 0.36-0.91). Studies using bulk analysis of hair or blood showed positive, but modest and more variable associations with AS and SSBs (R2 range 0.05-0.48). Few studies showed no association, particularly in non-United States populations and those with low AS and SSB intakes. Two studies provided evidence for CIR to detect changes in SSB intake in response to dietary interventions. Overall, the most compelling evidence supports CIR-Ala as an objective indicator of AS intake and breath CIR as an indicator of short-term AS intake. Considering how to adjust for underlying dietary patterns remains an important area of future work and emerging methods using breath and CSIA warrant additional investigation. More evidence is needed to refine the utility and specificity of CIRs to measure AS and SSB intake.

Meat consumption & positive mental health: A scoping review

The objective of this scoping review was to examine the breadth of the existing literature on the relation between meat consumption or meat abstention and positive psychological functioning. In April 2022, we conducted a systematic search of online databases (PubMed, PsycINFO, CINAHL Plus, Medline, Cochrane Library, and Web of Science) for primary research examining positive psychological functioning in meat consumers and those who abstain from meat. Thirteen studies met the inclusion/exclusion criteria, representing 89,138 participants (54,413 females and 33,863 males) with 78,562 meat consumers and 10,148 meat abstainers (13-102 years) from multiple geographic regions. The primary outcomes were life satisfaction, "positive mental health", self-esteem, and vigor. The secondary outcomes were "meaning in life", optimism, positive emotions, and psychological well-being. Eight of the 13 studies demonstrated no differences between the groups on positive psychological functioning, three studies showed mixed results, and two studies showed that compared to meat abstainers, meat consumers had greater self-esteem, "positive mental health", and "meaning in life". Studies varied substantially in methods and outcomes. Although a small minority of studies showed that meat consumers had more positive psychological functioning, no studies suggested that meat abstainers did. There was mixed evidence for temporal relations, but study designs precluded causal inferences. Our review demonstrates the need for future research given the equivocal nature of the extant literature on the relation between meat consumption and meat abstention and positive psychological functioning.

Is There a Convergence between the Food Classification Adopted by Food-Based Dietary Guidelines and Food Science and Technology?

The World Health Organization (WHO) proposed the dietary guidelines presented as the Food-based Dietary Guidelines (FBDG). The FBDG classify foods according to their origin, nature, nutrient source, food group, and processing level. Food science and technology (FST) ranks food according to its origin, perishability, nutrient source, processing, food group, and formulation. This paper aimed to compare the convergence points for food classification according to the FBDG and FST. This study was carried out in two phases. The first step was identifying the Food-Based Dietary Guidelines (FBDG). For each of the FBDG, food items were grouped as fruits, vegetables, cereals, sugars, fat and oils, legumes, foods from animals, dairy products, and others. The second step aimed to identify and describe the different food classification systems. The search was performed on PubMed®, Science Direct, and Web of Science and websites of international organizations such as the Food and Agriculture Organization of the United Nations (FAO), the World Health Organization (WHO), and the Codex Alimentarius. Our results show that the points of convergence between the classifications were the classification in terms of origin (animal and vegetable), nutrient sources, and food groups. However, inconsistencies were observed for the distribution of food items in each group in the 98 surveyed FBDG. As for nature, there was a convergence for in natura, minimally processed, and processed foods. However, the criteria adopted for minimally processed and processed foods described in the FBDG differ from those considered by the FST. FST also does not recognize the classification of foods concerning the level of processing.

The Impact of Free Sugar on Human Health-A Narrative Review

The importance of nutrition in human health has been understood for over a century. However, debate is ongoing regarding the role of added and free sugars in physiological and neurological health. In this narrative review, we have addressed several key issues around this debate and the major health conditions previously associated with sugar. We aim to determine the current evidence regarding the role of free sugars in human health, specifically obesity, diabetes, cardiovascular diseases, cognition, and mood. We also present some predominant theories on mechanisms of action. The findings suggest a negative effect of excessive added sugar consumption on human health and wellbeing. Specific class and source of carbohydrate appears to greatly influence the impact of these macronutrients on health. Further research into individual effects of carbohydrate forms in diverse populations is needed to understand the complex relationship between sugar and health.

Obesity Subtyping: The Etiology, Prevention, and Management of Acquired versus Inherited Obese Phenotypes

The etiology of obesity is complex and idiosyncratic-with inherited, behavioral, and environmental factors determining the age and rate at which excessive adiposity develops. Moreover, the etiologic status of an obese phenotype (how and when it developed initially) strongly influences both the short-term response to intervention and long-term health trajectories. Nevertheless, current management strategies tend to be 'one-size-fits-all' protocols that fail to anticipate the heterogeneity of response generated by the etiologic status of each individual's phenotype. As a result, the efficacy of current lifestyle approaches varies from ineffective and potentially detrimental, to clinically successful; therefore, we posit that effective management strategies necessitate a personalized approach that incorporates the subtyping of obese phenotypes. Research shows that there are two broad etiologic subtypes: 'acquired' and 'inherited'. Acquired obesity denotes the development of excessive adiposity after puberty-and because the genesis of this subtype is behavioral, it is amenable to interventions based on diet and exercise. Conversely, inherited obesity subsumes all forms of excessive adiposity that are present at birth and develop prior to pubescence (pediatric and childhood). As the inherited phenotype is engendered in utero, this subtype has irreversible structural (anatomic) and physiologic (metabolic) perturbations that are not susceptible to intervention. As such, the most realizable outcome for many individuals with an inherited subtype will be a 'fit but fat' phenotype. Given that etiologic subtype strongly influences the effects of intervention and successful health management, the purpose of this 'perspective' article is to provide a concise overview of the differential development of acquired versus inherited obesity and offer insight into subtype-specific management.

Color-based clustering algorithm as a novel image analytical method for characterizing maltose crystallinity in amorphous food models

Maltose crystallization affects the processibility and stability of sugar-rich foods. This study introduced a color-based clustering algorithm (CCA) to analyze crystallinity from the images of amorphous maltose/protein models. The XRD and DSC were also implemented in maltose crystallization characterization and validated the CCA analysis. The results indicated that CCA could effectively recognize maltose crystals (R = 0.9942), and amorphous maltose mainly crystallized to anhydrate α-maltose and β-maltose monohydrate according to its morphological aspects measured by CCA, XRD, and DSC. However, protein could change the mechanism of maltose crystal formation by disturbing the mutarotation and recrystallization processes of unstable β-maltose. Besides, maltose crystal formation and crystallinity were governed by molecular mobility as the CCA-derived Avrami indexes changed with the Strength parameter. Compared to XRD and DSC, the proposed CCA can provide a rapid and quantitative measure for maltose crystallinity and has great potential applications in the online detection of sugar crystallization.