Sugar-fat seesaw: a systematic review of the evidence

Carbohydrate Intake and Oral Glucose Tolerance Test Results in the Postpartum Period

CONTEXT

The American Diabetes Association (ADA) recommends a 3-day preparatory diet prior to a diagnostic oral glucose tolerance test (OGTT), a test often recommended in postpartum individuals with a history of gestational diabetes (GDM).

OBJECTIVE

Evaluate the relationship between carbohydrate intake and OGTT glucose in 2 cohorts of postpartum individuals.

METHODS

We performed analyses of postpartum individuals from 2 prospective studies with recent GDM (Balance after Baby Intervention, BABI, n = 177) or risk factors for GDM (Study of Pregnancy Regulation of INsulin and Glucose, SPRING, n = 104) .We measured carbohydrate intake using 24-hour dietary recalls (SPRING) or Food Frequency Questionnaire (BABI) and performed 2-hour 75-g OGTTs. The main outcome measure was 120-minute post-OGTT glucose.

RESULTS

There was no relationship between carbohydrate intake and 120-minute post-OGTT glucose level in either study population (SPRING: β = 0.03, [-5.5, 5.5] mg/dL, P = .99; BABI: β = -3.1, [-9.5, 3.4] mg/dL, P = .35). Adding breastfeeding status to the model did not change results (SPRING β = -0.14, [-5.7, 5.5] mg/dL, P = .95; BABI β = -3.9, [-10.4, 2.7] mg/dL, P = .25). There was, however, an inverse relationship between glycemic index and 120-minute post OGTT glucose (BABI: β = -1.1, [-2.2, -0.03] mg/dL, P = .04).

CONCLUSION

Carbohydrate intake is not associated with post-OGTT glucose levels among postpartum individuals. Dietary preparation prior to the OGTT may not be necessary in this population.

Trends in Loss-Adjusted Availability of Added Sugars and Energy Contribution from Macronutrients and Major Food Groups in Canada and the United States

A clear understanding of changes in the consumption of sugars and other sugars-containing foods has become essential for dietary recommendations and nutrition policy considerations. This study aimed to estimate the consumption trends of added sugars, energy, macronutrients, and food categories using food supply data.

Annual food availability data were obtained from Statistics Canada "Food Available in Canada" database and compared to the equivalent data from Canadian Community Health Survey 2004/2015 and USDA "Food Availability (Per Capita) Data System".

There was a 17% decline in the loss-adjusted per capita consumption of added sugars (%energy) in Canada over the past two decades, largely attributed to reduced intakes of refined sugar and sugars from soft drinks. Added sugars consumption was generally 30% less than that in the US. There was also a consistent decline in total energy intake and %energy from carbohydrates, accompanied by increased %energy derived from fats particularly during the most recent 10 years.

The observed trends in added sugars availability are similar to findings from the Canadian Community Health Surveys, demonstrating the potential application of annual loss-adjusted food availability data in monitoring trends in food and macronutrient intakes over time to complement dietary survey data in informing public policy development.

Reformulation of Processed Yogurt and Breakfast Cereals over Time: A Scoping Review

Poor diet is responsible for a quarter of European non-communicable disease (NCD)-related deaths. The reformulation of sugar, salt, and saturated fat in processed packaged foods offers an opportunity to reduce consumption of nutrients of concern and also support a reduction in energy intake. To date, there have been no publications measuring progress in food reformulation by compiling published evidence for a food category. The aim of this scoping review was to identify, characterize and summarise the findings of studies analysing the reformulation of processed yogurt and breakfast cereals. The review answered the research question: "What is the impact of food reformulation on the nutrient quality of yogurt and breakfast cereals available in the retail environment?" The research protocol was defined based on PRISMA-ScR guidelines. Five databases were searched in May 2022. Thirteen studies, published between 2010 and 2021 and completed across seven countries were eligible for inclusion. There were sufficient eligible studies to identify trends in sodium, salt, and sugar reduction in breakfast cereals. However, there was minimal or no reduction in energy, which may bring into question the use of food reformulation as part of an overall health strategy for obesity reduction.

Food portion sizes and their relationship with energy, and nutrient intakes in adolescents: The HELENA study

OBJECTIVES

This study aimed to investigate the associations between portion sizes (PSs) from different food groups and energy, as well as nutrient intakes in European adolescents.

METHODS

A sample of 1631 adolescents (54.2 % girls) were included from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional (HELENA) study. Mean food PS was calculated by dividing the total intake of the items by the number of eating occasions of these consumed items. To determine the key items for analysis, foods were ranked by frequency of consumption. A one-way between-groups analysis of covariance was used to test for significant differences in means across tertiles. A multivariable linear regression analysis was carried out, adjusting for age, sex, maternal education, body mass index, and using country as a level.

RESULTS

Energy intake increased with elevated intakes of energy-dense foods. Large portions of rice and other grains, starch roots and potatoes, and meat substitutes, nuts, and pulses were associated with increased carbohydrate and fiber intake. Larger portions of cheese and butter and animal fat were significantly associated with a higher fat intake. Lower intakes of some vitamins and micronutrients were noticed with consumption of larger portions of high energy-dense foods, such as desserts and pudding, margarine and vegetable oil, and butter and animal fat.

CONCLUSIONS

Large food PSs may be associated with positive energy, as well as macro- and micronutrient intake. Moreover, the findings from this study may help the future development of dietary guidance in general and specific to PSs, and support targeted strategies to address intakes of certain nutrients in European adolescents.

Association between added sugar intake and overall diet quality in the Finnish adult population

Added sugar intake has been associated with several health issues, but few studies have examined its association with overall diet quality. We aimed at examining the association between added sugar intake and overall diet quality in Finnish adults. Associations between added sugar intake and sociodemographic factors, lifestyle factors, and BMI were also explored. Our data comprised 5094 adults residing in Finland who participated in the National FinHealth 2017 Study. Dietary intake was assessed by a validated FFQ. Food consumption and nutrient intakes were calculated using the Finnish national food composition database. Added sugar intake was estimated based on food categorisation and identifying naturally occurring sugar sources. Overall diet quality was assessed by the modified Baltic Sea Diet Score. The average added sugar intake was 7·6 E % in women and 8·3 E % in men in this study population. Added sugar intake was inversely associated with education (P = 0·03 women; P = 0·001 men), physical activity (P < 0·0001), and BMI in men (P = 0·003), and directly with smoking (P = 0·002 women; P < 0·0001 men). Added sugar intake was inversely associated with overall diet quality in both sexes (P < 0·0001). No interactions were found except for men's physical activity subgroups, the inverse association being stronger among active men than moderately active or inactive men (P_{for interaction} = 0·005). Our findings suggest that high added sugar intake is associated with several unhealthy dietary and lifestyle habits, including poor-quality diets, smoking and leisure-time inactivity in Finnish adults. Efforts to improve diet quality should consider added sugar intake equally in the whole population.

Intakes of nutrients and food categories in Canadian children and adolescents across levels of sugars intake: cross-sectional analyses of the Canadian Community Health Survey 2015 Public Use Microdata File

Dietary recommendations to reduce sugars consumption may influence choices of sugars-containing foods and affect the intake of key micronutrients. We compared intakes of nutrients and food sources stratified by quintiles of total sugars in Canadian children (2-8 y) and adolescents (9-13 y, 14-18 y) using 24-hour dietary recalls from the 2015 Canadian Community Health Survey-Nutrition. Energy intakes did not differ across quintiles of sugars intake. Those with lower sugars intakes (Q1/Q3) generally had higher protein, fat, sodium, niacin, folate, and zinc and lower vitamin C compared with those with the highest sugars intakes (Q5). Q1 also had lower potassium but higher saturated fat compared with Q5. Further, Q1 generally had higher protein, fats, and niacin compared with Q3, while children in Q3 had higher potassium and riboflavin and older adolescents had higher calcium and fibre. Q5 had highest intakes of multiple sugar-containing food categories (e.g., fruit, confectionary, milks, cakes/pies/pastries), with higher sugars-sweetened beverages in adolescents. Q3 had higher fruit, milks, and fruit juice compared with Q1 and lower sugars/syrups/preserves, confectionary, and fruit juices compared with Q5. Certain nutrient-dense food sources of sugars (fruit, milks) may help increase key nutrients (potassium, calcium, fibre) in older adolescents with low sugars intakes. However, in those with the highest sugars intakes, nutrient-poor foods may displace nutrient-dense foods. Novelty: Canadian children and adolescents with lower sugars intake have better intakes of some nutrients. Energy intakes did not differ across sugars intake. Older adolescents with mean intakes of total sugars had better intakes of some key nutrients (potassium, calcium, fibre).

TAS1R2 sweet taste receptor genetic variation and dietary intake in Korean females

Taste receptor type 1, member 2 (TAS1R2) controls the oral sensing of sweetness. Genetic variations in TAS1R2 have been shown to be associated with differential sweetness intensity and varying carbohydrate intake levels among individuals. This study examined whether rs7534618 A > C in TAS1R2 is associated with dietary behavior and energy nutrient intake in Korean females. A cross-sectional design utilizing data from the Multi-Rural Communities Cohort Study, which was a nationwide epidemiological research project in Korea, was applied in this study. In total, 2198 females were analyzed to evaluate the differences in macronutrient intake levels and intake of carbohydrate-rich and sweet-tasting foods between the rs7534618 genotypes. The findings suggest that individuals with the CC minor genotype tended to have lower carbohydrate but higher fat intake than subjects with the A* genotype (p = 0.035 and p = 0.042, respectively). Subjects with the CC genotype also exhibited less intake of total grains but greater intake of bread than those with the A* genotype (p = 0.017 and p = 0.006, respectively). However, these observed associations were statistically modest (false discovery rate adjusted p > 0.05). In conclusion, TAS1R2 rs7534618 is not a decisive genetic modifier of nutrition and dietary intake in Korean females. However, given the paucity of studies, these putative associations between the TAS1R variation and dietary intake may be referred for further sensory genetic studies in Koreans.

Reformulation of sugar contents in Canadian prepackaged foods and beverages between 2013 and 2017 and resultant changes in nutritional composition of products with sugar reductions

Objective:

To quantify total sugar reformulation in Canadian prepackaged foods and beverages between 2013 and 2017 and identify changes in the nutritional composition of the foods and beverages reformulated to be lower in total sugar.

Design:

Longitudinal examination of foods and beverages present in both 2013 and 2017 collections of the University of Toronto’s Food Label Information Program database (n 6628 matched products). The proportion of products with changes in sugar levels was determined. Wilcoxon signed-rank test was used to examine changes in sugar levels overall for products lower or higher in sugar and changes in nutrient composition for products lower in sugar.

Setting:

Largest grocery retailers by market share in Canada.

Participants:

Canadian prepackaged foods and beverages.

Results:

The majority (76·6 %) of products had no change in total sugar content, 12·4 % were reformulated to be lower in sugar and 11·0 % were higher in sugar. A median sugar reduction of 19·0 % (1·6 g) was seen among products lower in sugar which was offset by a median 18·0 % (1·5 g) increase among products higher in sugar. Overall, median levels of energies and other nutrients stayed the same or decreased among products reformulated to be lower in sugar, the exception was for starch, which increased.

Conclusions:

Limited progress was made to reformulate foods and beverages to be lower in total sugar between 2013 and 2017. Results from this study identify areas in the food supply where attention may be needed to avoid unintended consequences of sugar-focused reformulation in terms of overall nutritional composition.

Canadian Adults with Moderate Intakes of Total Sugars have Greater Intakes of Fibre and Key Micronutrients: Results from the Canadian Community Health Survey 2015 Public Use Microdata File

Background: Global dietary guidelines recommend reducing free sugars intake, which may affect choices of sugars-containing foods, including important sources of key micronutrients. The purpose of the study was to compare the intakes of nutrients stratified by intakes of sugars in Canadian adults. Methods: The first-day 24-h dietary recalls from adults (n = 11,817) in the 2015 Canadian Community Health Survey-Nutrition were used to compare macronutrients, micronutrients and food categories across quintiles of total sugars [by %energy (%E)], adjusted for misreporting status and covariates. Results: Canadian adults consumed on average 86.9 g/day (18.8 %E) from total sugars and 47.5 g/day (9.9 %E) from free sugars. Mean intakes for the 1st (Q1), 3rd (Q3) and 5th (Q5) quintiles of total sugars were 7.9%E, 18.3%E and 33.3%E, respectively. Q3 had higher fibre, calcium, vitamin D, vitamin A, vitamin C and potassium intakes than Q1 (p < 0.001), reflecting higher fruit, milk and yogurt (p < 0.001) consumption. Compared to Q5, Q3 had higher intakes of folate, vitamin B₁₂, iron and zinc. Conclusion: This study provides the first detailed analyses of Canadian adults’ macro- and micro-nutrient intakes stratified by different intakes of total sugars. Moderate intakes of total sugars may result in greater intakes of fibre and micronutrients. Overall nutrient intake should be considered when making food choices.

Association between free sugars intake and nutrient dilution among Japanese adults: the 2016 National Health and Nutrition Survey, Japan

PURPOSE

The association between free sugars and nutrient intake is unclear in Japanese adults with relatively low free sugars intake. This cross-sectional study aimed to elucidate this relationship using data from the 2016 National Health and Nutrition Survey, Japan, and according to the current World Health Organization (WHO) guidelines for the prevention of nutrient dilution [< 5% or < 10% of energy (%E)].

METHODS

Dietary intake of Japanese adults (aged ≥ 20 years; n = 16,652) was assessed using a 1-day weighed dietary record. Mean intakes for selected nutrients and food groups were compared among categories of free sugars intake (i.e., < 2.5%E, 2.5 to < 5%E, 5 to < 10%E, and ≥ 10%E) by adjusting for sex, age, weight status, smoking status, habitual drinking, and occupation.

RESULTS

Free sugars intake was inversely associated with the intake of 16 of 24 micronutrients investigated. Compared to its lower categories of free sugars intake, significant reductions in intake were identified for almost all micronutrients at ≥ 10%E, whereas ten micronutrients were reduced at 5 to < 10%E. The intake of dietary fibre, sodium, potassium, calcium, and iron was lower at < 2.5%E than at 2.5 to < 5%E and/or 5 to < 10%E. Free sugars intake was also positively associated with sugars and jams, confectionaries, fruit and vegetable juices, and soft drinks and inversely with pulses and nuts and vegetables.

CONCLUSIONS

This study identified nutrient dilution among Japanese adults with higher free sugars intake and confirmed the significance of the WHO guidelines for preventing nutrient dilution in Japanese.

BMI modifies the effect of dietary fat on atherogenic lipids: a randomized clinical trial

BACKGROUND

SFA intake increases LDL cholesterol whereas PUFA intake lowers it. Whether the lipid response to dietary fat differs between normal-weight and obese persons is of relevance to dietary recommendations for obese populations.

OBJECTIVES

We compared the effect of substituting unsaturated fat for saturated fat on LDL cholesterol and apoB concentrations in normal-weight (BMI ≤ 25 kg/m2) and obese (BMI: 30-45) subjects with elevated LDL cholesterol.

METHODS

We randomly assigned 83 men and women (aged 21-70 y) stratified by BMI (normal: n = 44; obese: n = 39) and elevated LDL cholesterol (mean ± SD, normal weight 4.6 ± 0.9 mmol/L; obese 4.4 ± 0.8 mmol/L) to either a PUFA diet enriched with oil-based margarine ( n = 42) or an SFA diet enriched with butter (n = 41) for 6 wk.

RESULTS

Seven-day dietary records showed differences of ∼9 energy percent (E%) in SFA and ∼4 E% in PUFA between the SFA and PUFA groups. In the total study population, the PUFA diet compared with the SFA diet lowered LDL cholesterol (-0.31 mmol/L; 95% CI: -0.47, -0.15 mmol/L, compared with 0.32 mmol/L; 95% CI: 0.18, 0.47 mmol/L; P < 0.001) and apoB (-0.08 g/L; 95% CI: -0.11, -0.05 g/L, compared with 0.07 g/L; 95% CI: 0.03, 0.10 g/L; P < 0.001). Tests of the BMI × diet interaction were significant for total cholesterol, LDL cholesterol, and apoB ( P values ≤ 0.009). In normal-weight compared with obese participants post-hoc comparisons found that the respective changes in LDL cholesterol were 9.7% (95% CI: 5.3%, 14.2%) compared with 5.3% (95% CI: -0.7%, 11.2%), P = 0.206, in the SFA group, and -10.4% (95% CI: -15.2%, -5.7%) compared with -2.3% (95% CI: -7.4%, 2.8%), P = 0.020, in the PUFA group. ApoB changes were 7.5% (95% CI: 3.5%, 11.4%) compared with 3.0% (95% CI: -1.7%, 7.7%), P = 0.140, in the SFA group, and -8.9% (95% CI: -12.6%, -5.2%) compared with -3.8% (95% CI: -6.3%, -1.2%), P = 0.021, in the PUFA group. Responses to dietary fat were not associated with changes in polyprotein convertase subtisilin/kexin type 9 concentrations.

CONCLUSIONS

BMI modifies the effect of PUFAs compared with SFAs, with smaller improvements in atherogenic lipid concentrations in obese than in normal-weight individuals, possibly supporting adjustment of dietary recommendations according to BMI. This trial was registered with www.clinicaltrials.gov as NCT02589769.

Association of Dietary Fatty Acids with Blood Lipids is Modified by Physical Activity in Adolescents: Results from the GINIplus and LISA Birth Cohort Studies

The role of consuming different types of fatty acids (FA) at the expense of carbohydrates (CHO), on the blood lipid profile of adolescents is largely unknown, as is the modulating effect of different levels of physical activity (PA). Children from the GINIplus and LISA birth cohorts, with complete data on dietary FA (assessed by food-frequency questionnaires), objectively-measured PA (assessed by accelerometers) and blood lipids (lipoprotein cholesterol and triglycerides) at age 15 years, were included (N = 837). Sex-stratified associations between dietary FA and blood lipids were assessed by linear regression in substitution models which represented isocaloric replacements of CHO with saturated FA (SFA), monounsaturated FA (MUFA), n-3 polyunsaturated FA (PUFA) or n-6 PUFA. To assess the interactions with PA, analyses were then performed stratified by tertiles of different PA levels (sedentary, lifestyle, moderate-to-vigorous (MVPA)). Both sexes presented a significant inverse association between MUFA and triglycerides, and females a direct association between n-3 PUFA and high-density lipoprotein. Stratifying by PA tertiles, associations were mainly restricted to participants with the lowest levels of lifestyle PA, or the highest time spent sedentary. The effects of dietary FA on the lipid profile vary in an activity-specific manner, emphasizing possible synergistic roles of diet and PA.

The sweet taste signalling pathways in the oral cavity and the gastrointestinal tract affect human appetite and food intake: a review

Sweet taste is associated with food reward and energy source in the form of carbohydrate. Excessive sweet consumption is blamed for the prevalence of obesity. However, evidence for the potential of sweet taste to influence food intake and bodyweight regulation in humans remains unclear. The purpose of this review was to examine the physiological responses relevant to sweet taste mechanisms and the impact on appetite control. The literature was examined for studies that assessed the effects of non-nutritive sweeteners and natural sugars on hormonal secretions and neural activations via oral and gastrointestinal pathways. The findings indicated that a network of sweet taste signalling pathways in the oral cavity and the gut seem to mediate hormonal responses and some metabolism differences in neural circus that orchestrating the hunger-satiety cycle. Individual variations of sweet taste perception which is modulated by hormonal and genetic factors have been associated with dietary nutrient and sugar consumption.

Adiposity among 132 479 UK Biobank participants; contribution of sugar intake vs other macronutrients

Background

Policy makers are being encouraged to specifically target sugar intake in order to combat obesity. We examined the extent to which sugar, relative to other macronutrients, was associated with adiposity.

Methods

We used baseline data from UK Biobank to examine the associations between energy intake (total and individual macronutrients) and adiposity [body mass index (BMI), percentage body fat and waist circumference]. Linear regression models were conducted univariately and adjusted for age, sex, ethnicity and physical activity.

Results

Among 132 479 participants, 66.3% of men and 51.8% of women were overweight/obese. There was a weak correlation (r = 0.24) between energy from sugar and fat; 13% of those in the highest quintile for sugar were in the lowest for fat, and vice versa. Compared with normal BMI, obese participants had 11.5% higher total energy intake and 14.6%, 13.8%, 9.5% and 4.7% higher intake from fat, protein, starch and sugar, respectively. Hence, the proportion of energy derived from fat was higher (34.3% vs 33.4%, P < 0.001) but from sugar was lower (22.0% vs 23.4%, P < 0.001). BMI was more strongly associated with total energy [coefficient 2.47, 95% confidence interval (CI) 2.36-2.55] and energy from fat (coefficient 1.96, 95% CI 1.91-2.06) than sugar (coefficient 0.48, 95% CI 0.41-0.55). The latter became negative after adjustment for total energy.

Conclusions

Fat is the largest contributor to overall energy. The proportion of energy from fat in the diet, but not sugar, is higher among overweight/obese individuals. Focusing public health messages on sugar may mislead on the need to reduce fat and overall energy consumption.

Salivary leptin and TAS1R2/TAS1R3 polymorphisms are related to sweet taste sensitivity and carbohydrate intake from a buffet meal in healthy young adults

The influence of sweet taste sensitivity on food intake is not well understood. We investigated the involvement of salivary leptin and SNP of the sweet taste receptor genes (TAS1R2/TAS1R3) on sweet taste sensitivity, sensory-specific satiety (SSS) and macronutrient intake in healthy human adults. In all, nineteen high sweet sensitivity (HS) and eleven low sweet sensitivity (LS) subjects were classified based on the sweetness perception of one solution (9 mm sucrose) forced-choice triangle test. All participants completed a randomised crossover design experiment where they consumed one of three iso-energetic soup preloads differing in primary taste quality (sweet, non-sweet taste-control or no-taste energy-control). A period of 1 h after the preload, participants were offered a buffet meal consisting of foods varying in taste (sweet or non-sweet) and fat content. Subjective measures included hunger/fullness and SSS for sweetness. Saliva and buccal cells were collected to measure leptin level and to study the TAS1R2/TAS1R3 specific SNP, respectively. Salivary leptin concentrations were significantly higher in LS than HS participants (P<0·05). In addition, HS showed stronger sweet SSS compared with LH participants (P<0·05), and consumed less carbohydrate (% energy) and more non-sweet foods than LS (P<0·01 and P<0·05, respectively). Alleles from each TAS1R2 locus (GG compared with AA alleles of rs12033832, and CT/CC compared with TT alleles of rs35874116) were related to higher consumption of carbohydrates (% energy) and higher amount of sweet foods, respectively (P<0·05). In contrast, no associations were found for the TAS1R3 alleles. These results contribute to understand the links between taste sensitivity, macronutrient appetite and food consumption.

Examining the Relationship between Free Sugars and Calorie Contents in Canadian Prepacked Foods and Beverages

To align with broader public health initiatives, reformulation of products to be lower in sugars requires interventions that also aim to reduce calorie contents. Currently available foods and beverages with a range of nutrient levels can be used to project successful reformulation opportunities. The objective of this study was to examine the relationship between free sugars and calorie levels in Canadian prepackaged foods and beverages. This study was a cross-sectional analysis of the University of Toronto’s 2013 Food Label Database, limited to major sources of total sugar intake in Canada (n = 6755). Penalized B-spline regression modelling was used to examine the relationship between free sugar levels (g/100 g or 100 mL) and caloric density (kcal/100 g or 10mL), by subcategory. Significant relationships were observed for only 3 of 5 beverage subcategories and for 14 of 32 food subcategories. Most subcategories demonstrated a positive trend with varying magnitude, however, results were not consistent across related subcategories (e.g., dairy-based products). Findings highlight potential areas of concern for reformulation, and the need for innovative solutions to ensure free sugars are reduced in products within the context of improving overall nutritional quality of the diet.

Naturally occurring and added sugar in relation to macronutrient intake and food consumption: results from a population-based study in adults

Associations between sugar intake and the remaining diet are poorly described in modern food environments. We aimed at exploring associations of high naturally occurring and added sugar intakes with sociodemographic characteristics, intake of macronutrients, fibre and selected food groups. Our data comprised 4842 Finnish adults aged 25-74 years, who participated in the population-based DIetary, Lifestyle and Genetic determinants of Obesity and Metabolic syndrome (DILGOM) study. Diet was assessed by a validated 131-item FFQ. The food item disaggregation approach was used to estimate sucrose and fructose intakes from natural sources (naturally occurring sugar) and all other sources (added sugar). Sex-specific trends in macronutrient, fibre and food group intakes across sugar type quartiles were determined with general linear modelling adjusting for age, energy intake, leisure-time physical activity, smoking, education and BMI. Overall, results were similar across sexes. Young age was found to be a determinant of higher added sugar and lower naturally occurring sugar intakes (P < 0·0001). High added sugar intake was associated with low fibre intake (P < 0·0001) accompanied with lower fruit (P < 0·0001 women; P = 0·022 men) and vegetable consumption (P < 0·0001) and higher wheat consumption (P = 0·0003 women; P < 0·0001 men). Opposite results were found for naturally occurring sugar. Butter consumption increased by 28-32 % (P < 0·0001) when shifting from the lowest to the highest added sugar intake quartile, while a decrease of 26-38 % (P < 0·0001) was found for naturally occurring sugar. Therefore, the associations of sugar types with dietary carbohydrate and fat quality seem opposing. Proper adjustments with dietary variables are needed when studying independent relationships between sugar and health.

A meta-analysis of the relationship between brain dopamine receptors and obesity: a matter of changes in behavior rather than food addiction?

Addiction to a wide range of substances of abuse has been suggested to reflect a ‘Reward Deficiency Syndrome'. That is, drugs are said to stimulate the reward mechanisms so intensely that, to compensate, the population of dopamine D₂ receptors (DD2R) declines. The result is that an increased intake is necessary to experience the same degree of reward. Without an additional intake, cravings and withdrawal symptoms result. A suggestion is that food addiction, in a similar manner to drugs of abuse, decrease DD2R. The role of DD2R in obesity was therefore examined by examining the association between body mass index (BMI) and the Taq1A polymorphism, as the A1 allele is associated with a 30–40% lower number of DD2R, and is a risk factor for drug addiction. If a lower density of DD2R is indicative of physical addiction, it was argued that if food addiction occurs, those with the A1 allele should have a higher BMI. A systematic review found 33 studies that compared the BMI of those who did and did not have the A1 allele. A meta-analysis of the studies compared those with (A1/A1 and A1/A2) or without (A2/A2) the A1 allele; no difference in BMI was found (standardized mean difference 0.004 (s.e. 0.021), variance 0.000, Z=0.196, P<0.845). It was concluded that there was no support for a reward deficiency theory of food addiction. In contrast, there are several reports that those with the A1 allele are less able to benefit from an intervention that aimed to reduce weight, possibly a reflection of increased impulsivity.

Low Calorie Beverage Consumption Is Associated with Energy and Nutrient Intakes and Diet Quality in British Adults

It is unclear whether consumption of low-calorie beverages (LCB) leads to compensatory consumption of sweet foods, thus reducing benefits for weight control or diet quality. This analysis investigated associations between beverage consumption and energy intake and diet quality of adults in the UK National Diet and Nutrition Survey (NDNS) (2008–2011; n = 1590), classified into: (a) non-consumers of soft drinks (NC); (b) LCB consumers; (c) sugar-sweetened beverage (SSB) consumers; or (d) consumers of both beverages (BB), based on 4-day dietary records. Within-person data on beverage consumption on different days assessed the impact on energy intake. LCB consumers and NC consumed less energy and non-milk extrinsic sugars than other groups. Micronutrient intakes and food choices suggested higher dietary quality in NC/LCB consumers compared with SSB/BB consumers. Within individuals on different days, consumption of SSB, milk, juice, and alcohol were all associated with increased energy intake, while LCB and tea, coffee or water were associated with no change; or reduced energy intake when substituted for caloric beverages. Results indicate that NC and LCB consumers tend to have higher quality diets compared with SSB or BB consumers and do not compensate for sugar or energy deficits by consuming more sugary foods.