A medium-term intervention study on the impact of high- and low-fat snacks varying in sweetness and fat content: large shifts in daily fat intake but good compensation for daily energy intake

Imbalanced dietary patterns, anthropometric, and body composition profiles amongst adults with Down syndrome

Introduction: We aimed to analyze the anthropometric and body composition profiles of Down syndrome (DS) adults; to describe their dietary habits, nutrient intake, and physical activity patterns; and to identify the related risk factors which may influence their health status and quality of life.Methods: A cross-sectional study was conducted on a cohort of 23 DS adults (45% women) aged 21-44 years. Anthropometry and body composition were assessed by bioelectrical impedance. Dietary nutrient intake was assessed quantitatively using a 72-h recall. A food frequency questionnaire and the prevention with Mediterranean diet-PREDIMED questionnaire were used for qualitative rating.Results: Higher fat mass (FM) and lower lean mass (LM), bone mass (BM), and waist to hip ratio (WHR) were observed in women compared to men. LM and BM decreased, and body mass index (BMI), FM, and WHR increased with aging (all P < 0.05). Vitamin D and iodine intakes were not met by 70% and 60% of the studied participants, respectively. A total of 82% of the participants consumed less than 5 portions of fruits and vegetables per day and overconsumed food groups such as sweets and snacks and red meat (> 2 times per week). Protein intake showed a significant positive correlation with height (r = 0.489, P < 0.05), whereas fat intake was positively correlated with sweets and snacks (r = 0.521, P < 0.05).Conclusion: The present findings support the existence of poor anthropometric and body composition profiles, and diet quality, underscoring the need for an interdisciplinary team assessment to enhance health and quality of life in DS adults.

Effects of indulgent food snacking, with and without exercise training, on body weight, fat mass, and cardiometabolic risk markers in overweight and obese men

We hypothesized that exercise training would prevent gains in body weight and body fat, and worsening of cardiometabolic risk markers, during a 4-week period of indulgent food snacking in overweight/obese men. Twenty-eight physically inactive men (ages 19-47 yr) with body mass index (BMI) ≥25 kg/m2 consumed 48 donuts (2/day, 6 days/week; ~14,500 kcal total) for 4 weeks while maintaining habitual diet. Men were randomly assigned to control (n = 9), moderate-intensity continuous training (MICT; n = 9), or high-intensity interval training (HIIT; n = 10). Exercise training occurred 4 days/week, ~250 kcal/session. Controls did not increase body weight, body fat, or visceral abdominal fat. This was partially explained by a decrease in self-reported habitual energy (-239 kcal/day, p = 0.05) and carbohydrate (-47 g/day; p = 0.02) intake. Large inter-individual variability in changes in body weight, fat, and fat-free mass was evident in all groups. Fasting blood pressure, and blood concentrations of glucose, insulin, and lipids were unchanged in all groups. Glucose incremental area under the curve during an oral glucose tolerance test was reduced by 25.6% in control (p = 0.001) and 32.8% in MICT (p = 0.01) groups. Flow-mediated dilation (FMD) was not changed in any group. VO2max increased (p ≤ 0.001) in MICT (9.2%) and HIIT (12.1%) groups. We conclude that in physically inactive men with BMI ≥25 kg/m2 , consuming ~14,500 kcal as donuts over 4 weeks did not adversely affect body weight and body fat, or several markers of cardiometabolic risk. Consumption of the donuts may have prevented the expected improvement in FMD with HIIT.

Associations Between Habitual School-Day Breakfast Consumption Frequency and Academic Performance in British Adolescents

Studies indicate that breakfast positively affects learning in children. The present study aimed to examine associations between habitual school-day breakfast consumption frequency and academic performance, as measured by the General Certificate of Secondary Education (GCSE). The GCSE is a national academic qualification obtained by most British children during secondary education. Adolescents aged 16-18 years (n = 294; females: 77.2%) completed a retrospective 7-day food diary to report breakfast intake and a questionnaire to report GCSE grades. Breakfast was defined as any food or drink containing ≥5% of total energy expenditure (TEE) consumed up to 10:00 a.m. on school days. Habitual weekly school-day breakfast consumption frequency was categorized as rare (0-1 school days), occasional (2-3 school days), or frequent (4-5 school days). GCSE grades were aggregated into point scores and linear regression models were applied. Participants' GCSE grades in Mathematics and English were analyzed using ordinal logistic regression. Adolescents who rarely consumed breakfast on school days had a significantly lower capped point score (β = -0.13, p < 0.05) and mean point score (β = -0.14, p < 0.05) compared with frequent consumers. Low/middle socio-economic status (SES) adolescents who rarely consumed breakfast were significantly less likely to achieve higher Mathematics grades compared to low/middle SES adolescents who frequently consumed breakfast [adjusted cumulative odds ratio (OR): 0.35 95% confidence interval (CI): 0.17-0.72]. This cross-sectional study demonstrates that habitual school-day breakfast consumption amongst adolescents is a significant correlate of GCSE attainment. The results offer promising associative evidence which warrants further exploration in well controlled studies.

Energy compensation in the real world: good compensation for small portions of chocolate and biscuits over short time periods in complicit consumers using commercially available foods

While investigations using covert food manipulations tend to suggest that individuals are poor at adjusting for previous energy intake, in the real world adults rarely consume foods of which they are ill-informed. This study investigated the impact in fully complicit consumers of consuming commercially available dark chocolate, milk chocolate, sweet biscuits and fruit bars on subsequent appetite. Using a repeated measures design, participants received four small portions (4 × 10-11 g) of either dark chocolate, milk chocolate, sweet biscuits, fruit bars or no food throughout five separate study days (counterbalanced in order), and test meal intake, hunger, liking and acceptability were measured. Participants consumed significantly less at lunch following dark chocolate, milk chocolate and sweet biscuits compared to no food (smallest t(19) = 2.47, p = 0.02), demonstrating very good energy compensation (269-334%). No effects were found for fruit bars (t(19) = 1.76, p = 0.09), in evening meal intakes (F(4,72) = 0.62, p = 0.65) or in total intake (lunch + evening meal + food portions) (F(4,72) = 0.40, p = 0.69). No differences between conditions were found in measures of hunger (largest F(4,76) = 1.26, p = 0.29), but fruit bars were significantly less familiar than all other foods (smallest t(19) = 3.14, p = 0.01). These findings demonstrate good compensation over the short term for small portions of familiar foods in complicit consumers. Findings are most plausibly explained as a result of participant awareness and cognitions, although the nature of these cognitions cannot be discerned from this study. These findings however, also suggest that covert manipulations may have limited transfer to real world scenarios.

β-Glucan and dark chocolate: a randomized crossover study on short-term satiety and energy intake

Aim: The aims of this study were to adapt a traditional recipe into a healthier form by adding 3 g of oat β-glucan, substituting milk chocolate to dark chocolate with 70% cocoa, and to examine the effect of these alterations on short-term satiety and energy intake. Materials and Methods: Study subjects (n = 25) were tested in a randomized, crossover design with four products closely matched for energy content. Four different versions of a traditional recipe including milk chocolate-control (CON), oat β-glucan (B-GLU), dark chocolate (DARK) or oat β-glucan and dark chocolate (B-GLU + DARK) were given to subjects on different test days. After subjects were asked to report visual analog scale (VAS) scores on sensory outcomes and related satiety for four hours ad libitum, lunch was served and energy intake of individuals was measured. Results: VAS scores indicated that none of the test foods exerted an improved effect on satiety feelings. However, energy intake of individuals during ad libitum lunch was significantly lower in dark chocolate groups (CON: 849.46 ± 47.45 kcal versus DARK: 677.69 ± 48.45 kcal and B-GLU + DARK: 691.08 ± 47.45 kcal, p = 0.014). Conclusion: The study demonstrated that substituting dark chocolate for milk chocolate is more effective in inducing satiety during subsequent food intake in healthy subjects.

Meals and snacking, diet quality and energy balance

The present obesity "epidemic" has been attributed to a growing trend for snacking. Snacking may contribute to excess energy intake and weight gain through different ways, for example: context/environment of eating, frequency of consumption and quality of food choices. The present article reviews data and hypotheses about the role of snacks in diet quality and body weight control. One obvious difficulty in this field is the diversity of definitions and approaches used in cross-sectional, longitudinal, and intervention studies. A brief paragraph reviews the prevalence of snacking in various countries and its recent evolution. The literature addressing the contribution of snacks to daily energy and nutrient intake presents two contrasting pictures. In many reports, snacking appears to facilitate the adjustment of energy intake to needs, and to contribute carbohydrates, rather than fats, to the diet, in addition to valuable micronutrients. Such results are usually reported in healthy, normal-weight children and adults. By contrast, snacking often appears to contribute much energy but little nutrition in the diet of other consumers, particularly obese children and adults. In addition to selecting energy-dense foods, eating in the absence of hunger in response to external non-physiological cues, in an irregular fashion, in contexts (e.g. while watching television) that do not favor attention to the act of eating, might be crucial factors determining the nutritional effects of snacking. While efforts should be continued to harmonize definitions and minimize the influence of under-reporting, interventions aimed at decreasing detrimental snacking should address both food-related aspects and behavioral components.

Type of snack influences satiety responses in adult women

The effect of different snack foods on satiety and plasma glucose and hormone responses was assessed. Nineteen fasted adult women (mean age: 39.2 + or - 0.7 years, mean BMI: 26.1 + or - 0.8 kg/m(2)) consumed test foods including dried plums, low-fat cookies, white bread and water only on separate days. The test foods (with the exception of water) provided 238 kcal and were similar in total carbohydrate, fat and protein content but differed in fiber and sugar content. Subjects rated their feelings of hunger using satiety index scales prior to snack consumption and again every 15 min for 2h following initiation of intake. Blood samples were collected at baseline and 15, 30, 45, 60, 90, and 120 min following intake. At the end of the 120-min test period, subjects were presented with a meal to be consumed until satisfied. The satiety index AUC was greater for the dried plum trial versus the low-fat cookie trial (p < or = 0.05). There was no difference in post-snack consumption between the dried plums and cookie trials. The dried plums trial elicited lower plasma glucose and insulin AUC than the low-fat cookie trial (p < or = 0.05) and tended to promote a greater plasma ghrelin AOC (p = 0.056). These results demonstrate that consuming dried plums as a snack suppresses hunger relative to a low-fat cookie as evidenced by lower glucose and/or satiety-regulating hormone concentrations.

Small changes in snacking behaviour: the potential impact on CVD mortality

OBJECTIVE

To examine the potential public health impact on CHD and stroke mortality of replacing one 'unhealthy' snack with one 'healthy' snack per person, per day, across the UK population.

METHODS

Nutritional information was obtained for different 'unhealthy' (such as crisps, chocolate bars, cakes and pastries) and 'healthy' snack products (such as fresh fruit, dried fruit, unsalted nuts or seeds). Expected changes in dietary intake were calculated. The mean change in total blood cholesterol levels was estimated using the Keys equation. The effect of changing cholesterol and salt levels on CHD deaths and on stroke deaths was calculated using the appropriate equations from the Law and He meta-analyses. The estimated reductions in cardiovascular deaths were then tested in a sensitivity analysis.

RESULTS

Substituting one 'healthy' snack would reduce saturated fat intake by approximately 4.4 g per person per day, resulting in approximately 2400 fewer CHD deaths and 425 fewer stroke deaths per year. The associated 500 mg decrease in salt intake would result in approximately 1790 fewer CHD deaths and 1330 fewer stroke deaths.

CONCLUSIONS

Simply replacing one unhealthy snack with one healthy snack per day might prevent approximately 6000 cardiovascular deaths every year in the UK.

Altering the temporal distribution of energy intake with isoenergetically dense foods given as snacks does not affect total daily energy intake in normal-weight men

The objectives of the present study were to examine the effects of (1) ingesting mandatory snacks v. no snacks and (2) the composition of isoenergetically-dense snacks high in protein, fat or carbohydrate, on food intake and energy intake (EI) in eight men with ad libitum access to a diet of fixed composition. Subjects were each studied four times in a 9 d protocol per treatment. On days 1–2, subjects were given a medium-fat maintenance diet estimated at 1·6 × resting metabolic rate (RMR). On days 3–9, subjects consumed three mandatory isoenergetic, isoenergetically dense (380 kJ/100 g) snacks at fixed time intervals (11.30, 15.30 and 19.30 hours). Total snack intake comprised 30 % of the subjects' estimated daily energy requirements. The treatments were high protein (HP), high carbohydrate (HC), high fat (HF) and no snack (NS). The order was randomized across subjects in a counterbalanced, Latin-square design. During the remainder of the day, subjects had ad libitum (meal size and frequency) access to a covertly manipulated medium-fat diet of fixed composition (fat: carbohydrate: protein, 40:47:13 by energy), energy density 550 kJ/100 g. All foods eaten were investigator-weighed before ingestion and left-overs were weighed after ingestion. Subjective hunger and satiety feelings were tracked hourly during waking hours using visual analogue scales. Ad libitum EI amounted to 13·9 MJ/d on the NS treatment compared with 11·7, 11·7 and 12·2 MJ/d on the HP, HC and HF diets respectively (F(3,21) 5·35; P = 0·007, sed 0·66). Total EI values were not significantly different at 14·6, 14·5, 15·0 and 14·2 MJ/d respectively. Snack composition did not differentially affect total daily food intake or EI. Average daily hunger was unaffected by the composition of the snacks. Only at 12.00 hours did subjects feel significantly more hungry during the NS condition, relative to the other dietary treatments (F(3,18) 4·42; P = 0·017). Body weight was unaffected by dietary treatment. In conclusion, snacking per se led to compensatory adjustments in feeding behaviour in lean men. Snack composition (with energy density controlled) did not affect the amount eaten of a diet of fixed composition. Results may differ in real life where subjects can alter both composition and amount of food they eat and energy density is not controlled.

Comparison of high-fat and high-carbohydrate foods in a meal or snack on short-term fat and energy intakes in obese women

The present study aimed to compare the action of high-fat and high-carbohydrate (CHO) foods on meal size (satiation) and post-meal satiety in obese women. A within-subjects design was used; each participant received all four nutritional challenges. Fifteen healthy obese women (age 21–56 years, BMI 35–48 kg/m2) participated; thirteen completed all four test days. On two test days, participants were exposed to a nutritional challenge comprising an ad libitum high-fat or high-CHO lunch. On the other two test days they were exposed to a challenge comprising an ad libitum sweet high-fat or high-CHO mid-afternoon snack. Energy and macronutrient intakes were measured at each eating episode. Visual analogue rating scales were completed periodically to record subjective feelings of appetite. When offered a high-CHO selection of foods at lunch and mid-afternoon participants consumed less energy than when offered a high-fat selection. However, post-meal satiety was similar. Total test-day energy intake was significantly higher when high-fat foods were consumed at lunch, but not as a snack. Consumption of high-fat foods at a lunch and snack increased the amount of fat consumed over the whole test day. In conclusion, energy intake of an eating episode was influenced by nutrient composition in this group of obese women. Consumption of high-fat foods at lunch or as a snack led to overconsumption relative to high-CHO foods. However, high-fat foods at meals may have greater potential to influence daily intake than at snacks, probably because meals are larger eating episodes and therefore give greater opportunity to overconsume.

Effects of two weeks' mandatory snack consumption on energy intake and energy balance

OBJECTIVE

Our goal was to compare the effects of mandatory consumption of commercial snack products (CSPs) on energy intakes and energy balance in free-living adults and to assess the interaction between habitual level of CSP consumption and the interventions.

RESEARCH METHODS AND PROCEDURES

Four groups of 18 subjects (lean and overweight, males and females) were studied using a crossover design. Subjects consumed one type of CSP (high-carbohydrate, high-fat, or mixed composition) at three manipulations of energy 0 MJ (control), 1.5 MJ (low-energy), and 3.0 MJ (high-energy) each day during three 14-day interventions. The study design was parallel for type of CSP (macronutrient composition) and within-subjects for energy level. Subjects self-recorded food intakes between Days 8 and 14, and body weights were investigator-recorded on Days 1, 8, and 15 of each intervention period. Daily energy expenditure was estimated by heart rate monitoring.

RESULTS

Daily energy intakes increased from 10.4 MJ (control) to 11.1 MJ (low-energy) and 11.5 MJ (high-energy) (p < 0.001), resulting in a trend (not significant) for body weight gain. Energy balance was more positive when subjects were not recording their food intakes than when they were (p < 0.001). There was a trend (not significant) for greater increases in energy intake with increasing fat content, and energy density, of the interventions. Frequent CSP consumers compensated more for the interventions than did infrequent CSP consumers (R2 = 0.125, p = 0.003).

DISCUSSION

Subjects partially compensated for energy when supplemented with CSPs over 14-day periods, although this was insufficient to prevent some increase in energy balance. The level of compensation correlated with habitual energy intake from CSPs.

Is it possible to dissociate 'liking' and 'wanting' for foods in humans? A novel experimental procedure

Berridge's model (e.g. [Berridge KC. Food reward: Brain substrates of wanting and liking. Neurosci Biobehav Rev 1996;20:1-25.; Berridge KC, Robinson T E. Parsing reward. Trends Neurosci 2003;26:507-513.; Berridge KC. Motivation concepts in behavioral neuroscience. Physiol Behav 2004;81:179-209]) outlines the brain substrates thought to mediate food reward with distinct 'liking' (hedonic/affective) and 'wanting' (incentive salience/motivation) components. Understanding the dual aspects of food reward could throw light on food choice, appetite control and overconsumption. The present study reports the development of a procedure to measure these processes in humans. A computer-based paradigm was used to assess 'liking' (through pleasantness ratings) and 'wanting' (through forced-choice photographic procedure) for foods that varied in fat (high or low) and taste (savoury or sweet). 60 participants completed the program when hungry and after an ad libitum meal. Findings indicate a state (hungry-satiated)-dependent, partial dissociation between 'liking' and 'wanting' for generic food categories. In the hungry state, participants 'wanted' high-fat savoury>low-fat savoury with no corresponding difference in 'liking', and 'liked' high-fat sweet>low-fat sweet but did not differ in 'wanting' for these foods. In the satiated state, participants 'liked', but did not 'want', high-fat savoury>low-fat savoury, and 'wanted' but did not 'like' low-fat sweet>high-fat sweet. More differences in 'liking' and 'wanting' were observed when hungry than when satiated. This procedure provides the first step in proof of concept that 'liking' and 'wanting' can be dissociated in humans and can be further developed for foods varying along different dimensions. Other experimental procedures may also be devised to separate 'liking' and 'wanting'.

A substitution model of dietary manipulation is an effective means of optimising lipid profile, reducing C-reactive protein and increasing insulin-like growth factor-1

There are two key methods in which fat intake may be manipulated; the 'substitution model' and the 'reduction model'. However insufficient information is known about the mechanisms of dietary fat reduction in individuals who have successfully reduced their fat intake, to be clear as to which strategy offers the greatest chance of success. Our objective was to ascertain the most effective dietary intervention for improving cardiovascular risk profile. Eighty female volunteers (high fat consumers) were recruited. Each subject was randomly allocated into one of the following groups. Substitution of high-fat foods was made with reduced-fat products, by the reduction of high-fat foods, by a combination of substitution and reduction strategies, or no advice was given. Each intervention lasted 3 months. Anthropometric measures and fasting blood samples were taken at baseline and follow-up. The substitution intervention resulted in weight loss (mean -1.4 (95 % CI -2.4, -0.2) kg) and reduced percentage body fat (mean -1.3 (95% CI -2.0, -0.5)%). There was no significant weight change with the other interventions. Fasting triacylglycerols (-0.2 (SEM 0.07) mm; P=0.04), cholesterol and C-reactive protein (CRP) levels (0.8 (SEM 0.2) mg/l; P=0.04) fell with the substitution intervention, but not with the other interventions. Insulin-like growth factor-1 increased with both substitution and reduction (P=0.02). There was no significant change in fasting insulin or glucose with any intervention. The substitution model of dietary intervention is effective even over a relatively short interval of time in reducing fasting total cholesterol, triacylglycerols and CRP. Although the group size for the present study was small and involved females only, it has significant implications for population intervention strategies.

Associations between Food Variety and Body Fatness in Hong Kong Chinese Adults

BACKGROUND

Food variety is reported to be closely associated with body fatness in Caucasians. The association has not been examined in a Chinese population.

OBJECTIVE

To examine the association between food variety and body fatness in Hong Kong Chinese adults.

DESIGN

One hundred and twenty Hong Kong Chinese adults (aged 18-50 y). Usual dietary intake over a one-week period of all subjects was assessed by using a food frequency questionnaire. Anthropometric parameters were measured using standardized methods.

RESULTS

Varieties of grain and meat were negatively correlated with obesity indices (grain vs. BMI/body fat/waist/hip circumferences: partial r = -47/-0.43/-0.46/-0.42, p < 0.001; meat vs. BMI/body fat/waist/hip circumferences: partial r = -0.31/-0.24/-0.25/-0.29, p < 0.01). In contrast, there was a positive relationship between variety of snack and obesity indices (snack vs. BMI/body fat/waist/hip circumferences: partial r = 0.35/0.42/0.42/0.36, p < 0.001). A food variety ratio derived from varieties of snack, grain and meat, was a stronger predictor of body fat compared with dietary fat in a regression model.

CONCLUSION

Food variety may contribute to the local escalation in the prevalence of obesity. The variety of snack is the promoting factor for obesity while the variety of grains and meats may counteract its development. The findings of this study may have implications for treatment of obesity and the prevention of further weight gain.

A role for glucose and insulin preprandial profiles to differentiate meals and snacks

A physiological distinction between eating occasions may help account for contradictory findings on the role of eating frequency in energy homeostasis. We assessed this issue using a midafternoon eating occasion known in France as the goûter that often consists of snack foods. Among the 24 male subjects, 8 habitually consumed four meals per day, i.e., were usual goûter eaters (GE) and 16 habitually took 3 meals per day, i.e., usual non-goûter non-snack eaters (NGNSE). All subjects were time blinded from lunchtime and had to request subsequent meals. Blood was continuously withdrawn and collected with a change of tube every 10 min until dinner request. During the session, 8 of the non-goûter eaters (NGE) were offered a snack 210 min after lunch and were designated as non-goûter snack eaters (NGSE) if they ate. Results showed that the goûter was preceded by high hunger scores and a linear decline in plasma glucose (-9.0+/-3.0%, P<.05) and insulin concentrations (-22.9+/-6.0%, P<.05). These profiles were not observed before the snack. The dinner of GE was requested later and was smaller compared to NGNSE, whereas the snack altered neither time of request nor energy intake (EI) at dinner. Among blood variables, leptin at the onset of eating was the only factor that was predictive of both intermeal interval and EI. The glucose and insulin profiles indicate that snacks should not be considered as meals in studies on the role of eating frequency in energy homeostasis.

Adolescents’ attitudes about and consumption of low-fat foods: associations with sex and weight-control behaviors

The objective of the study was to examine adolescents' attitudes about and consumption of low-fat foods by sex and weight-control behaviors. Ninth- to 12th-grade students (n=1,083) in 20 Minnesota high schools completed mail surveys (response rate=74%) as part of baseline measurements (Fall 2001) in a randomized controlled trial (TACOS: Trying Alternative Cafeteria Options in Schools). Linear models examined attitudes and consumption of low-fat foods by sex and weight-control behaviors. Girls were more likely than boys to report positive attitudes and consumption of low-fat foods (all P<.01). Weight-control practices were associated with more positive attitudes about and higher consumption of low-fat foods. Promoting low-fat snacks to adolescents who are interested in weight control may be an effective component of nutrition intervention programs because these students have more positive attitudes about low-fat foods. Dietitians' efforts to educate adolescents about the benefits and healthfulness of low-fat foods would aid intervention programs.

Functional foods: psychological and behavioural functions

It is easier to demonstrate the consistent effects of foods on satiety than on cognitive performance. This is understandable since the satiety system incorporates physiological signalling systems that mediate the effects of foods on function. Specific manipulations of proteins, carbohydrates and fats have the potential to act as functional foods for appetite control. Because of the importance of the optimal functioning of cognitions for survival, these functions are quite strongly protected against short-term dietary and physiological perturbances. Therefore, food manipulations may be better detected through the degree of effort exerted to maintain performance rather than via changes in the actual performance itself. This procedure has not been widely used hitherto. The concept of biomarkers may have to be interpreted differently from research on physiological systems or clinical endpoints. For satiety, adjustments in the profile of hunger could serve as a biomarker or surrogate endpoint. For cognitions, correlated physiological variables may be more difficult to measure than the functional endpoint itself. Changes related to unitary functions (such as tracking) could serve as biomarkers for more complex, integrated skills (such as car driving). Since food manipulations may affect multiple functions, the challenge is to design foods with good satiety control that do not impair mental performance; or alternatively to engineer foods that optimise cognitive performance without compromising satiety. This rapidly developing field has great potential for close collaboration between academia and industry in the production of commercially successful products that show clear improvements in human functioning with the capacity to protect against disease or impairment.

Carbohydrates, appetite and feeding behavior in humans

The view of carbohydrates in relation to obesity has changed over the past few decades from being conducive to overconsumption and weight gain to being protective. This article reviews the mechanisms by which carbohydrate is purported to protect against weight gain. Although carbohydrate is metabolized and stored in the body less efficiently than fat, when de novo lipogenesis is invoked on very high carbohydrate diets, the beneficial effect on energy balance is likely to be minimal when typical high fat Western diets are consumed. However, it has been suggested that high carbohydrate foods may influence energy balance by reducing food intake through greater satiety effects, reducing energy density and displacing fat from the diet-the fat-sugar seesaw effect. To date, there seem to be few differences between sugars and starches on satiety and energy intake, but few studies have examined this. Some reduced-fat, and, therefore, higher carbohydrate, foods are highly energy dense. High carbohydrate foods do not necessarily have a low energy density. Evidence from recent studies suggests that adding carbohydrate, and especially sugar, to the diet neither displaces fat from the diet nor protects against elevated energy intake. Although it is easier to overeat on high fat than low fat foods, simply replacing fat with carbohydrate in the diet may not be as protective against overconsumption as the energy density or fat-sugar seesaw arguments suggest.

Significant increase in young adults' snacking between 1977-1978 and 1994-1996 represents a cause for concern!

BACKGROUND

Studies on children and adolescents suggest a large increase in the role of snacking; however, little is know about changes in the snacking behavior of young adults.

METHODS

USDA's nationally representative surveys from 1977-1978 to 1994-1996 are used to study snacking trends among 8,493 persons 19-29 years old.

RESULTS

Snacking prevalence increased from 77 to 84% between 1977-1978 and 1994-1996. The nutritional contribution of snacks to total daily energy intake went from 20 to 23%, primarily because energy consumed per snacking occasion increased by 26% and the number of snacks per day increased 14%. The mean daily caloric density (calorie per gram of food) of snacks increased from 1.05 to 1.32 calories. The energy contribution of high-fat desserts to the total calories from snacking decreased (22 to 14%), however, this food group remained the most important source of energy. The energy contribution of high-fat salty snacks doubled. Sweetened and alcoholic beverages remained important energy contributors.

CONCLUSION

This large increase in total energy and energy density of snacks among young adults in the United States may be contributing to our obesity epidemic.

Relation between consumption of sugar-sweetened drinks and childhood obesity: a prospective, observational analysis

BACKGROUND

The rising prevalence of obesity in children has been linked in part to the consumption of sugar-sweetened drinks. Our aim was to examine this relation.

METHODS

We enrolled 548 ethnically diverse schoolchildren (age 11.7 years, SD 0.8) from public schools in four Massachusetts communities, and studied them prospectively for 19 months from October, 1995, to May, 1997. We examined the association between baseline and change in consumption of sugar-sweetened drinks (the independent variables), and difference in measures of obesity, with linear and logistic regression analyses adjusted for potentially confounding variables and clustering of results within schools.

FINDINGS

For each additional serving of sugar-sweetened drink consumed, both body mass index (BMI) (mean 0.24 kg/m2; 95% CI 0.10-0.39; p=0.03) and frequency of obesity (odds ratio 1.60; 95% CI 1.14-2.24; p=0.02) increased after adjustment for anthropometric, demographic, dietary, and lifestyle variables. Baseline consumption of sugar-sweetened drinks was also independently associated with change in BMI (mean 0.18 kg/m2 for each daily serving; 95% CI 0.09-0.27; p=0.02).

INTERPRETATION

Consumption of sugar-sweetened drinks is associated with obesity in children.