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

Reasons for meal termination, eating frequency, and typical meal context differ between persons with and without a spinal cord injury

Overeating associated with neurogenic obesity after spinal cord injury (SCI) may be related to how persons with SCI experience satiation (processes leading to meal termination), their eating frequency, and the context in which they eat their meals. In an online, cross-sectional study, adults with (n = 688) and without (Controls; n = 420) SCI completed the Reasons Individuals Stop Eating Questionnaire-15 (RISE-Q-15), which measures individual differences in the experience of factors contributing to meal termination on five scales: Physical Satisfaction, Planned Amount, Decreased Food Appeal, Self-Consciousness, and Decreased Priority of Eating. Participants also reported weekly meal and snack frequency and who prepares, serves, and eats dinner with them at a typical dinner meal. Analysis revealed that while Physical Satisfaction, Planned Amount, and Decreased Food Appeal were reported as the most frequent drivers of meal termination in both groups, scores for the RISE-Q-15 scales differed across the groups. Compared to Controls, persons with SCI reported Physical Satisfaction and Planned Amount as drivers of meal termination less frequently, and Decreased Food Appeal and Decreased Priority of Eating more frequently (all p < 0.001). This suggests that persons with SCI rely less on physiological satiation cues for meal termination than Controls and instead rely more on hedonic cues. Compared to Controls, persons with SCI less frequently reported preparing and serving dinner meals and less frequently reported eating alone (all p < 0.001), indicating differences in meal contexts between groups. Individuals with SCI reported consuming fewer meals than Controls but reported a higher overall eating frequency due to increased snacking (p ≤ 0.015). A decrease in the experience of physical fullness, along with a dependence on a communal meal context and frequent snacking, likely contribute to overeating associated with neurogenic obesity after SCI.

Diet composition and energy intake in humans

Absolute energy from fats and carbohydrates and the proportion of carbohydrates in the food supply have increased over 50 years. Dietary energy density (ED) is primarily decreased by the water and increased by the fat content of foods. Protein, carbohydrates and fat exert different effects on satiety or energy intake (EI) in the order protein > carbohydrates > fat. When the ED of different foods is equalized the differences between fat and carbohydrates are modest. Covertly increasing dietary ED with fat, carbohydrate or mixed macronutrients elevates EI, producing weight gain and vice versa. In more naturalistic situations where learning cues are intact, there appears to be greater compensation for the different ED of foods. There is considerable individual variability in response. Macronutrient-specific negative feedback models of EI regulation have limited capacity to explain how availability of cheap, highly palatable, readily assimilated, energy-dense foods lead to obesity in modern environments. Neuropsychological constructs including food reward (liking, wanting and learning), reactive and reflective decision making, in the context of asymmetric energy balance regulation, give more comprehensive explanations of how environmental superabundance of foods containing mixtures of readily assimilated fats and carbohydrates and caloric beverages elevate EI through combined hedonic, affective, cognitive and physiological mechanisms. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Role of cholecystokinin in satiation: a systematic review and meta-analysis

The aim of this review was to examine: (1) the ability of cholecystokinin (CCK) or analogues of CCK to influence satiation and changes in body weight generally and (2) the efficacy of CCK in influencing satiation and eating behaviour specifically at physiological levels of dosing. A systematic review of the literature was performed following the PRISMA 2020 guidelines in five electronic databases investigating the effect of exogenous CCK or analogues on satiation and body weight. A meta-analysis of studies that infused CCK and measured satiation via changes in food/energy intake was also conducted. A total of 1054 studies were found using the search terms which were reduced to fifteen studies suitable for inclusion. Of the twelve studies measuring the effect on the weight of food ingested or energy intake, eleven showed a decrease. An analogue of CCK which can be administered orally failed to produce any weight loss at 24 weeks. The meta-analysis found the effect of CCK on satiation dosed at physiological levels was significant with a standardised mean difference of 0·57 (95 % CI 0·30, 0·85, P < 0·0001). By comparison, CCK dosed at higher, pharmacological levels also had a significant effect with a standardised mean difference of 0·91 (95 % CI 0·46, 1·36, P < 0·0001). Eight of the ten studies in the meta-analysis combined CCK infusion with some means to facilitate stomach distension. The present review found evidence that at both physiological and pharmacological levels of dosing CCK has a significant effect on satiation but no evidence for weight loss over the long term.

The consumption of energy dense snacks and some contextual factors of snacking may contribute to higher energy intake and body weight in adults

Preventing obesity (OB) among adults is a public health priority. One factor that seems to contribute to OB, due to the extra energy intake it involves, is the greater consumption of snacks. Whether snacking promotes OB in adults is however a source of controversy in the literature at present. The aim of this paper was to evaluate the effects of snacking on body weight status, along with contextual factors such as snacking location, food source, timing, and social context of snacking. To better understand the nature of snacking behavior, seven currently used definitions of snacking were described. Studies published prior to November 2020 were identified by searching the PubMed and Scopus databases, with thirty-three observational studies being identified and included. The consumption of energy-dense snacks may contribute to higher energy intake and weight in adult populations. The context in which adults snacks-such as eating alone, outside home or work, late in the day, in front of a TV or computer-is also important for this behavior. However, the lack of consensus on the definition of snacks in the literature makes these considerations suggestive rather than objective. Better-designed research is needed to determine the prospective association between snacking behavior and weight status in adults. Snacking may be an important behavior that can be modified to prevent obesity on the population level. Social education focused on promoting morning snacks and replacing energy-dense snacks by more nutritious ones, e.g. fruit and vegetables, may thus be beneficial.

Effects of snack intake during pregnancy and lactation on reproductive outcome in mild hyperglycemic rats

Metabolic disorders, like diabetes, as well as maternal diet, alter nutrient availability in utero, inducing adaptations in the offspring. Whether the effects of maternal hyperglycemia are modulated by diet, however, has yet to be explored. In the current study, we examined this issue by giving females rats, treated neonatally with STZ to induce mild hyperglycemia, and control littermates either ad libitum access to standard chow (Control n = 17; STZ n = 16) or standard chow and snacks (Control-snack n = 18; STZ-snack n = 19) (potato chips and a red fruit-flavored sucrose syrup solution 1.5%) throughout pregnancy and lactation. We hypothesized that the maternal glucose intolerance typically seen in female rats treated neonatally with STZ would be exacerbated by snack intake, and that the combination of snack intake and STZ treatment would lead to alterations in maternal behavior and offspring development. Maternal body weight and food intake were measured daily through pregnancy and lactation and litter weight throughout lactation. At birth, litter size, offspring weight, body length, and anogenital distance were obtained and offspring were classified according to their weight. Measures of nursing and retrieval behavior, as well as exploration in the open field and the elevated plus-maze were also recorded. As predicted, snack intake tended to aggravate the glucose intolerance of STZ-treated rats during pregnancy. Both Control and STZ-treated females that had access to snacks ate more calories and fat, but less carbohydrate and protein than females having access to chow alone. Overall, STZ-treated dams gave birth to fewer pups. Chow-fed STZ females gave birth to a greater proportion of large for pregnancy age pups, whereas dams in the Control-snack group gave birth to a greater proportion of small pups. The birth weight classification of pups born to STZ-snack rats, however, resembled that of the Control chow-fed females. Although all litters gained weight during lactation, litters from snack-fed dams gained less weight regardless of maternal hyperglycemia and did not show catch-up growth by weaning. Overall, STZ rats spent more time nest building, whereas the average inter milk ejection interval was higher in snack-fed females. STZ-snack dams retrieved the complete litter faster than dams in the other groups. Together, these data suggest that when mild hyperglycemic females are given access to snacks throughout pregnancy and lactation their intake is similar to that of Control females given snack access. The combination of hyperglycemia and snack access tended to decrease glucose tolerance in pregnancy, and normalized birth weight classification, but produced few other effects that were not seen as a function of snack intake or hyperglycemia alone. Since birth weight is a strong predictor of health issues, future studies will further investigate offspring behavioral and metabolic outcomes later in life.

ImpulsePal: The systematic development of a smartphone app to manage food temptations using intervention mapping

BACKGROUND

Impulsive processes driving eating behaviour can often undermine peoples' attempts to change their behaviour, lose weight and maintain weight loss.

AIM

To develop an impulse management intervention to support weight loss in adults.

METHODS

Intervention Mapping (IM) was used to systematically develop the "ImpulsePal" intervention. The development involved: (1) a needs assessment including a qualitative study, Patient and Public advisory group and expert group consultations, and a systematic review of impulse management techniques; (2) specification of performance objectives, determinants, and change objectives; (3) selection of intervention strategies (mapping of change techniques to the determinants of change); (4) creation of programme materials; (5) specification of adoption and implementation plans; (6) devising an evaluation plan.

RESULTS

Application of the IM Protocol resulted in a smartphone app that could support reductions in unhealthy (energy dense) food consumption, overeating, and alcoholic and sugary drink consumption. ImpulsePal includes inhibition training, mindfulness techniques, implementation intentions (if-then planning), visuospatial loading, use of physical activity for craving management, and context-specific reminders. An "Emergency Button" was also included to provide access to in-the-moment support when temptation is strong.

CONCLUSIONS

ImpulsePal is a novel, theory- and evidence-informed, person-centred app that aims to support impulse management for healthier eating. Intervention Mapping facilitated the incorporation of app components that are practical operationalisations of change techniques targeting our specific change objectives and their associated theoretical determinants. Using IM enabled transparency and provided a clear framework for evaluation, and enhances replicability and the potential of the intervention to accomplish the desired outcome of facilitating weight loss through dietary change.

Snacking may improve dietary fiber density and is associated with a lower body mass index in postmenopausal women

OBJECTIVES

This study aimed to examine the relationship between eating frequency (EF), meal frequency, and snacking frequency (SF), and the body weight status of postmenopausal women. We tested how meal frequency and SF were related with macronutrient intake, and how different definitions of snacking affected the study results.

METHODS

Dietary intake was assessed using a 3-d food diary in 302 women age 45 to 65 y. Body weight, body fat percentage, and waist circumference were measured, and the body mass index (BMI) was computed. Women were classified as overweight-to-obese or of normal weight. Eating occasions that provided at least 50 kcal were classified as meals or snacks based on three definitions: Contribution to total energy intake (EI; ≥15% as a meal, <15% as a snack), self-reported, and based on time.

RESULTS

When adjusted for confounders and the EI:estimated energy requirement, a negative association was seen between EF, self-reported SF, and BMI. EF and self-reported SF were negatively associated with EI. Differences in the dietary composition of the snacks between the groups were seen when identified by participants themselves. Specifically, the percentage energy from total sugar and alcohol in self-reported snacks was significantly lower, but dietary fiber density was significantly higher among normal-weight compared with overweight-to-obese women.

CONCLUSIONS

Higher EF and self-reported SF, independently of the EI:estimated energy requirement, is associated with lower BMI values and EI in postmenopausal women. Snacking may improve the dietary fiber density of the diet. An objective definition of snacking needs to be used in nutritional studies.

Self-reported food intake decreases over recording period in the National Diet and Nutrition Survey

From 2008, the UK's National Diet and Nutrition Survey (NDNS) changed the method of dietary data collection from a 7-d weighed diary to a 4-d unweighed diary, partly to reduce participant burden. This study aimed to test whether self-reported energy intake changed significantly over the 4-d recording period of the NDNS rolling programme. Analyses used data from the NDNS years 1 (2008/2009) to 8 (2015/2016) inclusive, from participants aged 13 years and older. Dietary records from participants who reported unusual amounts of food and drink consumed on one or more days were excluded, leaving 6932 participants. Mean daily energy intake was 7107 kJ (1698 kcal), and there was a significant decrease of 164 kJ (39 kcal) between days 1 and 4 (P < 0·001). There was no significant interaction of sex or low-energy reporter status (estimated from the ratio of reported energy intake:BMR) with the change in reported energy intake. The decrease in reported energy intake on day 4 compared with day 1 was greater (P < 0·019) for adults with higher BMI (>30 kg/m2) than it was for leaner adults. Reported energy intake decreased over the 4-d recording period of the NDNS rolling programme suggesting that participants change their diet more, or report less completely, with successive days of recording their diet. The size of the effect was relatively minor, however.

Within-person compensation for snack energy by US adults, NHANES 2007-2014

BACKGROUND

Most Americans snack and some snack several times a day; however, compensatory dietary and eating behaviors associated with snacking in free-living individuals are poorly understood.

OBJECTIVE

The aim of the study was to examine within-person differences in reported energy intake and eating patterns on a snack day relative to a no-snack day.

METHODS

We used 2 d of dietary recall data from the NHANES 2007-2014 to replicate the crossover nutrition study paradigm in a natural setting. Respondents reporting a snack episode in only one of two available dietary recalls were eligible for inclusion in the study (n = 1,917 men and 1,860 women). We used multivariable regression methods to compare within-person differences in quantitative, qualitative, and eating pattern outcomes between the snack and no-snack recall days.

RESULTS

On the snack day, snack episodes provided (mean difference and 95% CI) 493 (454, 532) kcal of energy in men and 360 (328, 392) kcal in women. The 24-h energy intake on snack day was higher by 239 (140, 337) kcal in men and 219 (164, 273) kcal in women (P < 0.0001). On the snack day, both men and women were more likely to skip main meals and reported lower energy intake from main meals (P < 0.0001); however, the energy density of foods or beverages reported on the snack compared with no-snack days were not different. Fruit servings were higher on the snack day (P ≤ 0.0004), but intakes of vegetables and key micronutrients did not differ. The 24-h ingestive period was longer on the snack day (P < 0.0001).

CONCLUSIONS

Free-living men and women partially compensated for snack energy by decreasing energy intake from main meals without adverse associations with qualitative dietary characteristics or time of meal consumption. Women compensated to a smaller extent than men. Thus, over the long term, snack episodes may contribute to positive energy balance, and the risk may be higher in women.

The Response of More Health Focused and Less Health Focused People to a Physical Activity Calorie Equivalent Label on Discretionary Snack Foods

A Physical Activity Calorie Equivalent (PACE) label shows the minutes of physical activity required to burn off the caloric content of a particular food. This study investigated the influence of PACE labelling on liking and consumption of discretionary snack foods in a group of more health focused and less health focused consumers. Participants (n = 97) tasted and rated (i.e., liking, prospective consumption) a range of snack foods with or without a PACE label. Total sampling consumption was also measured. Participants completed a shortened version of the International Physical Activity Questionnaire and the General Health Interest Scale questionnaire. Paired samples t-test, independent samples t-tests, a General Linear Model and Chi-Square tests were used to check for statistical significance. For more health focused participants (n = 57), the PACE label decreased only liking (p = 0.02). The PACE label was not effective in reducing liking (p = 0.49), prospective consumption (defined as the amount of the sample participants thought that they could consume) (p = 0.10) or consumption (p = 0.41) of energy-dense discretionary snack foods for less health focused individuals (n = 40). The level of participants’ physical activity did not facilitate the influence of PACE labelling on liking, consumption or prospective consumption. The PACE label was found to not be effective among less health focused individuals or the overall sample population. Therefore, the PACE label may not be an effective labelling strategy to reduce the liking or consumption of discretionary snack foods.

Effects of protein supplements consumed with meals, versus between meals, on resistance training-induced body composition changes in adults: a systematic review

Context

The impact of timing the consumption of protein supplements in relation to meals on resistance training-induced changes in body composition has not been evaluated systematically.

Objective

The aim of this systematic review was to assess the effect of consuming protein supplements with meals, vs between meals, on resistance training-induced body composition changes in adults.

Data Sources

Studies published up to 2017 were identified with the PubMed, Scopus, Cochrane, and CINAHL databases.

Data Extraction

Two researchers independently screened 2077 abstracts for eligible randomized controlled trials of parallel design that prescribed a protein supplement and measured changes in body composition for a period of 6 weeks or more.

Results

In total, 34 randomized controlled trials with 59 intervention groups were included and qualitatively assessed. Of the intervention groups designated as consuming protein supplements with meals (n = 16) vs between meals (n = 43), 56% vs 72% showed an increase in body mass, 94% vs 90% showed an increase in lean mass, 87% vs 59% showed a reduction in fat mass, and 100% vs 84% showed an increase in the ratio of lean mass to fat mass over time, respectively.

Conclusions

Concurrently with resistance training, consuming protein supplements with meals, rather than between meals, may more effectively promote weight control and reduce fat mass without influencing improvements in lean mass.

Replacing American snacks with tree nuts increases consumption of key nutrients among US children and adults: results of an NHANES modeling study

Background

Replacing typical American snacks with tree nuts may be an effective way to improve diet quality and compliance with the 2015–2020 Dietary Guidelines for Americans (DGAs).

Objective

To assess and quantify the impact of replacing typical snacks with composite tree nuts or almonds on diet metrics, including empty calories (i.e., added sugars and solid fats), individual fatty acids, macronutrients, nutrients of public health concern, including sodium, fiber and potassium, and summary measures of diet quality.

Methods

Food pattern modeling was implemented in the nationally representative 2009–2012 National Health and Examination Survey (NHANES) in a population of 17,444 children and adults. All between-meal snacks, excluding beverages, were replaced on a per calorie basis with a weighted tree nut composite, reflecting consumption patterns in the population. Model 1 replaced all snacks with tree nuts, while Model 2 exempted whole fruits, non-starchy vegetables, and whole grains (>50% of total grain content). Additional analyses were conducted using almonds only. Outcomes of interest were empty calories (i.e., solid fats and added sugars), saturated and mono- and polyunsaturated fatty acids, fiber, protein, sodium, potassium and magnesium. The Healthy Eating Index-2010, which measures adherence to the 2010 Dietary Guidelines for Americans, was used as a summary measure of diet quality.

Results

Compared to observed diets, modeled food patterns were significantly lower in empty calories (−20.1% and −18.7% in Model 1 and Model 2, respectively), added sugars (−17.8% and −16.9%), solid fats (−21.0% and −19.3%), saturated fat (−6.6% and −7.1%)., and sodium (−12.3% and −11.2%). Modeled patterns were higher in oils (65.3% and 55.2%), monounsaturated (35.4% and 26.9%) and polyunsaturated fats (42.0% and 35.7%), plant omega 3 s (53.1% and 44.7%), dietary fiber (11.1% and 14.8%), and magnesium (29.9% and 27.0%), and were modestly higher in potassium (1.5% and 2.9%). HEI-2010 scores were significantly higher in Model 1 (67.8) and in Model 2 (69.7) compared to observed diets (58.5). Replacing snacks with almonds only produced similar results; the decrease in sodium was more modest and no increase in plant omega-3 fats was observed.

Conclusion

Replacing between-meal snacks with tree nuts or almonds led to more nutrient-rich diets that were lower in empty calories and sodium and had more favorable fatty acid profiles. Food pattern modeling using NHANES data can be used to assess the likely nutritional impact of dietary guidance.

Impact of food supplementation on weight loss in randomised-controlled dietary intervention trials: a systematic review and meta-analysis

Dietary trials provide evidence for practice and policy guidelines, but poor adherence may confound results. Food supplementation may improve adherence to dietary interventions, but the impact of supplementation on study outcomes is not known. The aim of this review was to examine the impact of food supplementation on weight loss in dietary intervention trials. The databases Scopus, PubMed and the Cochrane Library were searched for dietary intervention trials published between January 2004 and March 2015 using the following keyword combinations: ‘trial’ OR ‘intervention’, ‘food’ OR ‘diet’, ‘weight loss’ and ‘adherence’ OR ‘adherence’. Studies were included if food was provided to at least one study group and both ‘weight change’ and ‘adherence’ were reported. Random effects meta-analyses were conducted to assess weighted mean differences (WMD) in body weight (change or final mean values). The included studies formed two groups: trials involving an intervention group supplemented with a food and a control without food supplementation (food v. no food), and trials in which food was provided to all subjects (food v. food) (PROSPERO registration: CRD42015017563). In total, sixteen studies were included. Significant weight reduction was reported in the food v. no food studies (WMD −0·74 kg; 95 % CI −1·40, −0·08; P=0·03, I2=63 %). A non-significant increase in weight was found among the food v. food studies (WMD 0·84 kg; 95 % CI −0·60, 2·27; P=0·25, I2=0 %). Food supplementation appeared to result in greater weight loss in dietary trials. Energy restrictions and intensity of interventions were other significant factors influencing weight loss.

Using food intake records to estimate compliance with the Eatwell Plate dietary guidelines

BACKGROUND

The UK Eatwell Plate is consumer based advice recommending the proportions of five food groups for a balanced diet: starchy foods, fruit and vegetables, dairy foods, nondairy sources of protein and foods and drinks high in fat or sugar. Many foods comprise ingredients from several food groups and consumers need to consider how these fit with the proportions of the Eatwell Plate. This involves disaggregating composite dishes into proportions of individual food components. The present study aimed to match the diets of adults in Scotland to the Eatwell Plate dietary recommendations and to describe the assumptions and methodological issues associated with estimating Eatwell Plate proportions from dietary records.

METHODS

Foods from weighed intake records of 161 females and 151 males were assigned to a single Eatwell group based on the main ingredient for composite foods, and the overall Eatwell Plate proportions of each subject's diet were calculated. Food group proportions were then recalculated after disaggregating composite foods.

RESULTS

The fruit and vegetables and starchy food groups consumed were significantly lower than recommended in the Eatwell Plate, whereas the proportions of the protein and foods high in fat or sugar were significantly higher. Failing to disaggregate composite foods gave an inaccurate estimate of the food group composition of the diet.

CONCLUSIONS

Estimating Eatwell Plate proportions from dietary records is not straightforward, and is reliant on methodological assumptions. These need to be standardised and disseminated to ensure consistent analysis.

Patterns of Food Consumption are Associated with Obesity, Self-Reported Diabetes and Cardiovascular Disease in Five American Indian Communities

The relationship between dietary patterns and chronic disease is underexplored in indigenous populations. We assessed diets of 424 American Indian (AI) adults living in 5 rural AI communities. We identified four food patterns. Increased prevalence for cardiovascular disease was highly associated with the consumption of unhealthy snacks and high fat-food patterns (OR 3.6, CI=1.06, 12.3; and OR 6.0, CI=1.63, 22.1), respectively. Moreover, the food-consumption pattern appeared to be different by community setting (p<.05). We recommend culturally appropriate community-intervention programs to promote healthy behavior and to prevent diet-related chronic diseases in this high-risk population.

Evidence for efficacy and effectiveness of changes in eating frequency for body weight management

In self-reported diets of free living individuals, frequent eating is associated with higher energy intake, yet beliefs about the possible beneficial effect of higher eating frequency for managing body weight persist. Prospective cohort studies and controlled trials of manipulation of eating frequency published by 31 December 2012 were reviewed to assess whether variation in eating frequency may be an adjunct to weight management. Four prospective cohort studies were identified; 2 of these included adults followed for 10 y and 2 followed pre-adolescent/adolescent girls for 6 or 10 y. Within each age category, the findings of the 2 studies were contradictory. Six controlled trials with adult subjects serving as their own controls found no significant changes in body weight due to manipulation of eating frequency interventions lasting 6-8 wk. In 6 additional intervention trials of 8-52 wk duration, free-living adults were counseled to change the eating frequency of self-selected food intake with no significant differences in weight loss attributable to eating frequency. Overall, the consistency of the null findings from controlled trials of manipulation of eating frequency for promoting weight loss suggests that beliefs about the role of higher eating frequency in adult weight management are not supported by evidence. Interpretation of the evidence from published observational studies is complicated by differences in definition of eating frequency and limited knowledge of systematic and random errors in measurement of eating frequency.

Predicting adult weight change in the real world: a systematic review and meta-analysis accounting for compensatory changes in energy intake or expenditure

BACKGROUND

Public health and clinical interventions for obesity in free-living adults may be diminished by individual compensation for the intervention. Approaches to predict weight outcomes do not account for all mechanisms of compensation, so they are not well suited to predict outcomes in free-living adults. Our objective was to quantify the range of compensation in energy intake or expenditure observed in human randomized controlled trials (RCTs).

METHODS

We searched multiple databases (PubMed, CINAHL, SCOPUS, Cochrane, ProQuest, PsycInfo) up to 1 August 2012 for RCTs evaluating the effect of dietary and/or physical activity interventions on body weight/composition.

INCLUSION CRITERIA

subjects per treatment arm ≥5; ≥1 week intervention; a reported outcome of body weight/body composition; the intervention was either a prescribed amount of over- or underfeeding and/or supervised or monitored physical activity was prescribed; ≥80% compliance; and an objective method was used to verify compliance with the intervention (for example, observation and electronic monitoring). Data were independently extracted and analyzed by multiple reviewers with consensus reached by discussion. We compared observed weight change with predicted weight change using two models that predict weight change accounting only for metabolic compensation.

FINDINGS

Twenty-eight studies met inclusion criteria. Overfeeding studies indicate 96% less weight gain than expected if no compensation occurred. Dietary restriction and exercise studies may result in up to 12-44% and 55-64% less weight loss than expected, respectively, under an assumption of no behavioral compensation.

INTERPRETATION

Compensation is substantial even in high-compliance conditions, resulting in far less weight change than would be expected. The simple algorithm we report allows for more realistic predictions of intervention effects in free-living populations by accounting for the significant compensation that occurs.

Snack food intake in ad libitum fed rats is triggered by the combination of fat and carbohydrates

Snack food like potato chips substantially contributes to energy intake in humans. In contrast to basic food, snacks are consumed additionally to other meals and may thereby lead to non-homeostatic energy intake. Snack food is also frequently associated with hedonic hyperphagia, a food intake independent from hunger. Analysis of brain activity patterns by manganese-enhanced MRI has previously revealed that the intake of potato chips in ad libitum fed rats strongly activates the reward system of the rat brain, which may lead to hedonic hyperphagia. The purpose of the present study was to develop a two-choice preference test to identify molecular determinants of snack food triggering extra food intake in ad libitum fed rats. Different kinds of test food were presented three times a day for 10 min each time. To minimize the influence of organoleptic properties, each test food was applied in a homogenous mixture with standard chow. Food intake as well as food intake-related locomotor activity were analyzed to evaluate the effects induced by the test foods in the two-choice preference test. In summary, fat (F), carbohydrates (CH), and a mixture of fat and carbohydrates (FCH) led to a higher food intake compared to standard chow. Notably, potato chip test food (PC) was highly significantly preferred over standard chow (STD) and also over their single main macronutrients F and CH. Only FCH induced an intake comparable to PC. Despite its low energy density, fat-free potato chip test food (ffPC) was also significantly preferred over STD and CH, but not over F, FCH, and PC. Thus, it can be concluded that the combination of fat and carbohydrates is a major molecular determinant of potato chips triggering hedonic hyperphagia. The applied two-choice preference test will facilitate future studies on stimulating and suppressive effects of other food components on non-homeostatic food intake.

Measuring the difference between actual and reported food intakes in the context of energy balance under laboratory conditions

To date, no study has directly and simultaneously measured the discrepancy between what people actually eat and what they report eating under observation in the context of energy balance (EB). The present study aimed to objectively measure the ‘extent’ and ‘nature’ of misreporting of dietary intakes under conditions in which EB and feeding behaviour were continuously monitored. For this purpose, a total of fifty-nine adults were recruited for 12 d, involving two 3 d overt phases and two 3 d covert phases of food intake measurement in a randomised cross-over design. Subjects had ad libitum access to a variety of familiar foods. Food intake was covertly measured using a feeding behaviour suite to establish actual energy and nutrient intakes. During the overt phases, subjects were instructed to self-report food intake using widely accepted methods. Misreporting comprised two separate and synchronous phenomena. Subjects decreased energy intake (EI) when asked to record their food intake (observation effect). The effect was significant in women ( − 8 %, P< 0·001) but not in men ( − 3 %, P< 0·277). The reported EI was 5 to 21 % lower (reporting effect) than the actual intake, depending on the reporting method used. Semi-quantitative techniques gave larger discrepancies. These discrepancies were identical in men and women and non-macronutrient specific. The ‘observation’ and ‘reporting’ effects combined to constitute total misreporting, which ranged from 10 to 25 %, depending on the intake measurement assessed. When studied in a laboratory environment and EB was closely monitored, subjects under-reported their food intake and decreased the actual intake when they were aware that their intake was being monitored.

The assessment of eating behaviour in children who are obese: a psychological approach. A position paper from the European childhood obesity group

OBJECTIVE

This paper introduces health professionals to the different psychological models thought to influence eating behaviour in the absence of hunger in children who are obese and to propose a method of assessing these behaviours in practice.

METHODS

Clinical researchers from the European Childhood Obesity Group (ECOG) adopted an evidence-based approach to examine the literature concerning the assessment of eating behaviour in children who are obese. Studies published in English were filtered out of the medical and psychological literature from 1960 to the present, and the resulting bibliography was searched for relevant articles. Key themes from the current evidence were compiled and classified according to the underpinning psychological models. Based on the current evidence and the authors' combined clinical experience, a three-staged approach to assessment was agreed by consensus.

RESULTS

Valid and reliable tools for assessing and monitoring each of the three identified models (Dietary Restraint Theory, Emotional Eating and the Diathesis-Stress Model) are suggested for use in clinical practice, and the ECOG three-staged approach to assessing eating behaviours in the absence of hunger is described.

CONCLUSIONS

This paper presents practical guidance on how to assess eating behaviour in the absence of hunger in children who are clinically obese and suggests a focus for future research.

Myths, presumptions, and facts about obesity

BACKGROUND

Many beliefs about obesity persist in the absence of supporting scientific evidence (presumptions); some persist despite contradicting evidence (myths). The promulgation of unsupported beliefs may yield poorly informed policy decisions, inaccurate clinical and public health recommendations, and an unproductive allocation of research resources and may divert attention away from useful, evidence-based information.

METHODS

Using Internet searches of popular media and scientific literature, we identified, reviewed, and classified obesity-related myths and presumptions. We also examined facts that are well supported by evidence, with an emphasis on those that have practical implications for public health, policy, or clinical recommendations.

RESULTS

We identified seven obesity-related myths concerning the effects of small sustained increases in energy intake or expenditure, establishment of realistic goals for weight loss, rapid weight loss, weight-loss readiness, physical-education classes, breast-feeding, and energy expended during sexual activity. We also identified six presumptions about the purported effects of regularly eating breakfast, early childhood experiences, eating fruits and vegetables, weight cycling, snacking, and the built (i.e., human-made) environment. Finally, we identified nine evidence-supported facts that are relevant for the formulation of sound public health, policy, or clinical recommendations.

CONCLUSIONS

False and scientifically unsupported beliefs about obesity are pervasive in both scientific literature and the popular press. (Funded by the National Institutes of Health.).

Snack frequency: associations with healthy and unhealthy food choices

Objective

We examined associations between snack frequency, sociodemographic characteristics, BMI, dietary and eating behaviour. In order to identify whether various subgroups of high-frequency snack consumers exist, we investigated underlying food patterns and lifestyle factors.

Design

The data were based on the Swiss Food Panel Questionnaire of 2010, which included an FFQ, questions relating to sociodemographics and lifestyle factors. Data were examined using ANOVA, regression analysis and hierarchical cluster analysis. Gender differences were also investigated in the analysis of the data.

Setting

A sample of 6189 adults participating in the Swiss Food Panel filled in a questionnaire (response rate 30 %).

Subjects

The sample consisted of both men and women, with a mean age of 54·4 (sd 13·5) years.

Results

There was no association between snack frequency and BMI. Consumption frequency of sweets and savouries as well as fruit intake increased with increasing snack frequency. Additionally, three different subgroups of high-frequency snack consumers could be revealed: healthy, moderate and unhealthy dietary-pattern groups. The latter included respondents who were less health-conscious and was characterized by high alcohol consumption frequency, daily breakfast skipping and watching television during the main meal.

Conclusions

High snack frequency occurred in the context of healthy as well as unhealthy dietary behaviour and lifestyle patterns. Women made healthier dietary food choices and were more likely to consume fruits as snacks, while men chose unhealthy foods, such as sweets and savouries, more often.

Acute effects of aerobic exercise on mood and hunger feelings in male obese adolescents: a crossover study

BACKGROUND

The aim of this study was to determine the acute effects of exercise intensity on anxiety, mood states and hunger in obese adolescents.

METHODS

Subjects were eight male obese adolescents (age 15.44 ± 2.06 y; BMI 33.06 ± 4.78 kg/m2). Each subject underwent three experimental trials: (1) Control, seated for 30 min; (2) Low intensity exercise (LIE)--exercise at 10% below ventilatory threshold (VT); (3) High intensity exercise (HIE)--exercise at 10% above VT. Anxiety (STAI Trait/State), mood (POMS) and hunger (VAS) were assessed before and immediately after the experimental sessions. Comparisons between trials and times were assessed using Kruskal-Wallis and Wilcoxon tests, respectively. Associations between variables were described using a Spearman test.

RESULTS

The largest increase in hunger was observed after LEI (914.22%). Both exercise sessions increased anxiety, fatigue and decreased vigor (p < 0.05).

CONCLUSIONS

Acute exercise bouts are associated with negative changes in anxiety and mood, and with increases in hunger in obese adolescents.

No consistent association between consumption of energy-dense snack foods and annual weight and waist circumference changes in Dutch adults

BACKGROUND

There is conflicting evidence regarding an association between the consumption of energy-dense snack (EDS) foods and the development of overweight.

OBJECTIVE

In the current study, we examined whether there was an association between the intake of EDS foods and annual weight and waist circumference changes in normal-weight and overweight Dutch adults.

DESIGN

The study population included 9383 men and women from the MORGEN-EPIC (Monitoring Project on Risk Factors for Chronic Diseases in the Netherlands-European Prospective Investigation into Cancer and Nutrition) study, which is a population-based cohort study in 3 towns in the Netherlands (Amsterdam, Maastricht, and Doetinchem), who had a body mass index (in kg/m(2)) <30 and who were not dieting. Participants were enrolled between 1993 and 1997 and followed for an average of 8.1 y (Amsterdam and Maastricht: 9.9 y; Doetinchem: 4.9 y). Intake of EDS foods (sweets, cakes and pastries, and savory snacks) was assessed at baseline by using a validated food-frequency questionnaire. Multivariate linear and multinomial logistic regression models were applied and stratified by center to examine the association between energy from EDS foods (kcal) and annual weight and waist circumference changes.

RESULTS

The mean (±SD) daily energy intake from EDS foods was 294 ± 192 kcal. In Amsterdam and Maastricht, the annual weight change was 168 ± 572 g/y, whereas in Doetinchem, the annual weight change was 444 ± 816 g/y. In the multivariate regression analysis adjusted for follow-up duration and anthropometric, dietary, and lifestyle factors, there was some, but inconsistent, evidence of an association of EDS-food consumption with annual weight change.

CONCLUSION

Our study provides some, but inconsistent, evidence that consumption of EDS foods is positively associated with an increase in annual weight in normal- to overweight Dutch adults.

Understanding the influence of the snack definition on the association between snacking and obesity: a review

The aim of the present study is to understand how different definitions of snacking influence the estimated probability of obesity in the presence of concurrent risk factors. Factors influencing obesity were evaluated by reviewing the relevant literature through a PUBMED search. Six different modalities to define snack consumption were identified. A Bayesian network model in which nodes represent the variables that the retrieved studies indicate as affecting the probability of obesity was implemented and used to estimate the individual risk of developing obesity taking into account the concurrent effect of the considered risk factors. For a subject with a given profile of factors, the probability of obesity varies according to the chosen definition of snacking, up to maximum of 70%. The variability of the probability of obesity attributable to the chosen definition of snacking is very high and may threaten any conclusion about the effect of snacking, which may be related to the specific definitions adopted in the study.

The satiety effect of disguised liquid preloads administered acutely and differing only in their nutrient content tended to be weaker for lipids but did not differ between proteins and carbohydrates in human subjects

Whether protein is the macronutrient with the strongest satiety effect remains a matter of debate because of the diversity of study designs employed. The aim of the present study was to compare the effect of different liquid preloads made up of proteins, fats or carbohydrates only, under stringently controlled conditions, on satiety. Fifty-six subjects participated in the present study which consisted of four randomised test days, i.e. 1 d per macronutrient and one control day. During each test day, the subjects were required to consume the preload in full, and then their subsequent food intake was measured. The volunteers were divided into two groups: the first (T0) group, which consumed the preload immediately before lunch, and the second (T1) group, which consumed it 1 h beforehand. The main results showed that the participants consumed significantly less at lunch following the consumption of all three preloads than on the no-preload day, and consumed less after the consumption of the carbohydrate preload than after the consumption of the lipid preload. When energy from the preload was included, overall energy intake was significantly greater in all the three preload conditions than in the situation involving no preload, with only partial compensation for preload energy in all conditions. Total daily energy intake was highest after the lipid preload ingestion, but this could be a chance finding since it was not significantly higher than that observed after protein or carbohydrate preload ingestion. No significant effects of the interval between the preload and test meal ingestion were found. These results do not confirm the greater satiety effect of proteins than of carbohydrates, but partially confirm the weaker effect of fats.

The rationale behind small food store interventions in low-income urban neighborhoods: insights from New Orleans

Environmental approaches to the obesity problem in the US have garnered favor due to growing evidence that changes to the environment are at the root of the epidemic. Low-income urban neighborhoods, where obesity rates are disproportionately high, typically lack supermarkets yet have a high density of small food stores. This may increase the risk for unhealthy diets and obesity for neighborhood residents, because small stores carry mostly energy-dense foods and few fruits and vegetables. This paper pulls together various studies and pilot work conducted in New Orleans to explore the rationale behind small store interventions. Many low-income residents in New Orleans live within walking distance of small food stores and shop at them frequently. Marketing research has documented that changes to in-store shelf space and displays of specific foods affect the sales of these foods. Initiatives in New Orleans and elsewhere have demonstrated some success with improving healthy food availability in small stores, and an intercept survey of customers at small stores suggests that customers would purchase more fruits and vegetables if available. Efforts to encourage small store operators to offer a healthier mix of foods may, in the end, depend on the profitability of such changes. Evidence from a typical small store in New Orleans indicates that a greater percentage of gross profits come from snack foods and beverages than from fruits and vegetables. More research is needed to better understand the financial operations of small food stores and whether altering the mix of foods is economically feasible.

The influence of weekday eating patterns on energy intake and BMI among female elementary school personnel

Many health practitioners recommend eating small, frequent meals for weight loss, yet the relationship of eating patterns, such as eating occasion frequency (EOF), to energy intake and body weight is controversial. Broad-based efforts to promote worksite wellness programs increase the importance of this issue, as many work environments inherently restrict eating patterns. The eating patterns of school personnel are understudied, but are of particular interest, not only because they have limited eating opportunities during the day but also because their diet and weight outcomes are likely to influence behaviors of a much larger population. We examined relationships between weekday EOF and energy intake and BMI among female elementary school personnel in 22 schools in a suburban county of southeastern Louisiana. Two 24-h dietary recalls were administered to randomly-selected employees (n = 329) on nonconsecutive days by registered dietitians. Measured heights and weights were used to calculate BMI (weight/height(2)). On average, employees consumed 2.2 of their total 5.9 meals and snacks during the school day, accounting for 37% of daily energy. In multiple regression models controlling for demographic and health variables, EOF as well as separate counts of meal and snack frequency were each positively and significantly associated with energy intake. However, neither the number of meals, snacks, nor overall EOF was associated with BMI. The proportion of energy consumed during the school day and the positive association of weekday EOF with energy intake suggest an important role for worksite wellness programs that target the dietary improvement of elementary school personnel.

Satiation due to equally palatable sweet and savory meals does not differ in normal weight young adults

Sensory properties are greatly involved in the process of satiation. Regarding the nature of sensory signals, an important distinction can be made between sweet and savory taste. It is unclear, however, whether sweet and savory differ in their influence on satiation. Our objective was to investigate the difference between a sweet and savory taste on satiation, independent of palatability, texture, energy density, and macronutrient composition. A crossover design was used, consisting of 3 test conditions in which 2 tastes (sweet and savory) were compared. Sixty-four healthy, nonsmoking, unrestrained participants (18 males and 46 females), with a mean age of 22.3 +/- 2.4 y and a mean BMI of 21.6 +/- 1.7 kg/m(2), enrolled. Rice was used as a test meal served in either a sweet or savory version. The meals were similar in palatability, texture, energy density, and macronutrient composition. Ad libitum intake, eating rate, and changes in pleasantness and appetite during the meals were measured. Ad libitum intake did not differ between the 2 meals; participants ate a mean of 314 +/- 144 g of the sweet meal and 333 +/- 159 g of the savory meal. Eating rate (sweet, 38 +/- 14 g/min; savory, 37 +/- 14 g/min) and changes in pleasantness and appetite during the meals were similar. Homogeneous meals with a sweet or savory taste, similar in palatability, texture, energy density, and macronutrient composition, do not differ in their influence on satiation in normal weight young adults.

Association between eating frequency, weight, and health

There is speculation amongst health professionals, the media, and the public regarding eating frequency (EF) and its impact on weight and health. Nutritional weight-loss and -maintenance interventions of longer than 1 week's duration were reviewed for associations between EF and weight and health. Of the 176 studies identified, 25 relevant studies matched the criteria and only 10 of these were weight-loss interventions. Generally, sample sizes were small, interventions were short-term, and a wide array of definitions was used to define an eating occasion. Several key outcomes such as physical activity, adherence to assigned EF, and hunger were often not measured. The limited evidence available suggests there is no association between EF and weight or health in either weight-loss or -maintenance interventions, with a possible inverse association between EF and lipids in weight-maintenance interventions. Longer term, larger studies that include important weight and health outcomes are needed.