F. Bellisle

Early adiposity rebound: causes and consequences for obesity in children and adults.

Childhood obesity is an important public health problem, with a rapidly increasing frequency worldwide. Identification of critical periods for the development of childhood and adolescent obesity could be very useful for targeting prevention measures. Weight status in early childhood is a poor predictor of adult adiposity status, and most obese adults were not obese as children. We first proposed to use the body mass index (BMI) charts to monitor individual BMI development. The adiposity rebound (AR) corresponds to the second rise in BMI curve that occurs between ages 5 and 7 years. It is not as direct a measure as BMI at any age, but because it involves the examination of several points during growth, and because it is identified at a time when adiposity level clearly change directions, this method provides information that can help us understand individual changes and the development of health risks. An early AR is associated with an increased risk of overweight. It is inversely associated with bone age, and reflects accelerated growth. The early AR recorded in most obese subjects and the striking difference in the mean age at AR between obese subjects (3 years) and non-obese subjects (6 years) suggest that factors have operated very early in life. The typical pattern associated with an early AR is a low BMI followed by increased BMI level after the rebound. This pattern is recorded in children of recent generations as compared to those of previous generations. This is owing to the trend of a steeper increase of height as compared to weight in the first years of life. This typical BMI pattern (low, followed by high body fatness level) is associated with metabolic diseases such as diabetes and coronary heart diseases. Low body fatness before the AR suggests that an energy deficit had occurred at an early stage of growth. It can be attributable to the high-protein, low-fat diet fed to infants at a time of high energy needs, the former triggering height velocity and the latter decreasing the energy density of the diet and then reducing energy intake. The high-fat, low-protein content of human milk may contribute to its beneficial effects on growth processes. Early (pre- and postnatal) life is a critical period during which environmental factors may programme adaptive mechanisms that will persist in adulthood. Under-nutrition in fetal life or during the first years after birth may programme a thrifty metabolism that will exert adverse effects later in life, especially if the growing child is exposed to overnutrition. These observations stress the importance of an adequate nutritional status in childhood and the necessity to provide nutritional intakes adapted to nutritional needs at various stages of growth. Because the AR reflects particular BMI patterns, it is a useful tool for the paediatrician to monitor the childs adiposity development and for researchers to investigate the different developmental patterns leading to overweight. It contributes to the understanding of chronic disease programming and suggests new approaches to obesity prevention.

Body mass index in 7-9-y-old French children: frequency of obesity, overweight and thinness.

OBJECTIVE: To assess the frequency of different grades of nutritional status (obesity, overweight and thinness) in French children aged 7–9u2005y using four current definitions based on body mass index (BMI).METHODS: Data were collected in 2000 in a randomly selected sample of French children following the protocol recommended by the European Childhood Obesity Group (ECOG). After computing the BMI (weight/height squared), four references were used to define grades of nutritional status: (1) the French references to define thinness and overweight (3rd and 97th percentiles respectively); (2) the Must et al references to define thinness, overweight and obesity (5th, 85th and 95th percentiles respectively); (3) the International Obesity Task Force cut-offs to define overweight and obesity; and (4) the Center for Disease Control 2000 references to define thinness, overweight and obesity (5th, 85th and 95th percentiles respectively).RESULTS: Age and gender standardized frequencies were estimated in 1582 children. According to the French, Must et al, IOTF and CDC references, overweight (including obesity) affected 16.3, 23.9, 18.1 and 20.6% of children, respectively; obesity affected 9.3, 3.8 and 6.4% of children according to the Must, IOTF and CDC references, respectively. Thinness was present in 3.9, 6.0 and 6.0% of children according to the French, Must and CDC references. Whatever the definition, little difference was observed between sexes. Through age classes, as a rule, overweight and obesity tended to decrease while thinness tended to increase.CONCLUSION: The present study revealed an increasing prevalence of overweight in comparison with previous French data and a trend for increasing prevalence of thinness. The IOTF-based prevalence of overweight (including obesity) in 2000 in France was similar with the prevalence recorded in the late 1980s in the USA and the prevalence of obesity in 2000 in France was similar to the prevalence of obesity in the late 1970s in the USA. Data in France are comparable to those reported in other studies conducted in Western Europe. This study provides baseline information for analysis of time trends and for geographical comparisons.

Contribution of snacks and meals in the diet of French adults: a diet-diary study

To investigate the relative contributions of meals and snacks in the daily intake of free-living humans, 54 French adults maintained food intake diaries for four 7-day periods. They recorded all food and fluid intakes mentioning whether, in their opinion, each intake event was a snack or a meal. The weekly food diaries also contained information on the circumstances of each event such as time and place, number of persons present, and affective states (hunger, satiety, etc.) before and after intake. On average, 2.7 meals and 1.3 snacks were consumed each day. Very few days included no snacking. Total daily energy and nutrient intake were not different between days with and days without snacks. Snacks differed from meals in several dimensions. Meals were about twice as large as snacks in energy and weight. Nutrient intake, in absolute values, was higher in meals. In proportions, however, snacks contained more CHO and less fat and proteins. Most foods were consumed in larger amounts in the context of meals but a few (sweets, cereal bars, biscuits, and sodas) were mostly consumed as snacks. Hunger was more intense before but less intense after meals than snacks. The satiety ratio was higher for snacks than meals. Time of day affected many intake parameters. For example, afternoon snacks exhibited a high satiety ratio for a modest intake. The present study describes the status of several potential determining factors at the time of snacks in humans, demonstrating a specific role for snacks, as opposed to meals, in the daily eating pattern of healthy adults.

Dietary patterns and their sociodemographic and behavioural correlates in French middle-aged adults from the SU.VI.MAX cohort.

Background/Objectives:Few studies have investigated dietary patterns among French adults. We aimed to identify dietary patterns and their relation with nutrient intakes, sociodemographic, lifestyle and other health indicators in a large population of middle-aged subjects living in France.Subjects/Methods:Dietary patterns were identified using factor analysis in 5194 women and men aged 45–60 years enrolled in the SU.VI.MAX (Supplémentation en Vitamines et Minéraux Antioxydants) study. Dietary data were based on repeated 24-h dietary records (at least six records during 2 years).Results:Four patterns were identified: (1) ‘alcohol and meat products’; (2) ‘prudent diet’; (3) ‘convenience foods’; and (4) ‘starch, sauces, and vegetables’. The first pattern was positively associated with low education, smoking and overweight in both genders, as well as with abdominal obesity in women and treated hyperlipidaemia and/or hypertension in men. The second pattern was positively correlated with high education and being older than 55 years and negatively correlated with current smoking. This pattern was also associated with overweight and low waist circumference in women and with hyperlipidaemia treatment in men. The third pattern was inversely related to age and positively related to higher education in both genders. In men, higher scores were related to living alone and an urban residence. The fourth pattern was associated with high education and an urban residence in men only.Conclusions:Our study identified four dietary patterns in this population of French middle-aged adults. Associations with sociodemographic, behavioural and health-related factors were found to differ according to dietary patterns. Sex-specific relationships were also found.

Eating Patterns in French Subjects Studied by the “Weekly Food Diary” Method ☆

The weekly food diary was translated and adapted for use by French subjects. This validated method requires subjects to record every food and drink intake over 1 week, with several descriptors of the physical, psychological and social circumstances. Ten male [age 23. 6+/-2.3 years, body mass index (BMI) 20.7+/-0.6] and 16 female (age 23.3+/-0.6 years, BMI 20+/-0.6) students completed four weekly diaries over 1 year, one per season. Data were processed using a specially designed software. Breakfast was important, (about 400 kcalories). Lunch and dinner were almost equal in energy content but alcohol was consumed mainly with dinner. Meal size correlated positively with premeal hunger, number of people present, duration of premeal interval and time of day. Postmeal satiety correlated positively with meal size, aftermeal stomach content, and negatively with time of day, postmeal hunger and duration of sleep the preceding night. These observations allow hypotheses to be developed about mechanisms of intake in a French population and cross-cultural comparisons to be made.

Eating behaviour in obese patients with melanocortin-4 receptor mutations: a literature review

Melanocortin-4 receptor (MC4R) mutations are the most common known cause of monogenic obesity and an important contributor to polygenic obesity. MC4R mutations with partial or total loss of function, as well as the variant rs17782313 mapped near MC4R, are positively associated with obesity. MC4R is involved in the leptin–melanocortin signalling system, located in hypothalamic nuclei, that controls food intake via both anorexigenic or orexigenic signals. Impairment in this receptor might affect eating behaviours. Thus, in the case of MC4R mutation carriers, obesity could be related, at least partly, to inadequate control over eating behaviours. Many published studies address eating behaviours in MC4R mutation carriers. Most studies focus on binge eating disorder, whereas others examine various aspects of intake and motivation. Up to now, no evaluation of this literature has been performed. In this review, we examine the available literature on eating behaviours in carriers of MC4R mutations and variant rs17782313 near MC4R gene. We address binge eating disorder, bulimia nervosa, mealtime hyperphagia, snacking, psychological factors, satiety responsiveness and intake of energy and macro/micronutrient. In a small number of studies, MC4R mutations seem to impair eating behaviours or motivation, but no clear causal effects can be found in the balance of the evidence presented. Improvements in methodologies will be necessary to clarify the behavioural effects of MC4R mutations.

Central adiposity in Brazilian schoolchildren aged 7-10 years.

Waist circumference (WC) is a measure of central adiposity related to elevated risk factor levels in children and adolescents. The aim of the present study was to describe WC percentiles in 7- to 10-year-old Brazilian children and to compare frequencies of obesity and overweight as defined by BMI and frequencies of excess and at risk of abdominal adiposity as defined by WC to the corresponding age and sex data from British references. A representative sample of 2919 schoolchildren of the city of Florianopolis (southern Brazil) was examined. Smoothed WC percentiles were derived using the least mean square method. Frequencies of overweight and obesity and of excess and at risk of abdominal adiposity were assessed using the 91st and 98th centiles of the British references as cut-off points. WC increased with age in both boys and girls, with higher values for boys at every age and percentile level. Nutritional status categories of children assessed by the 91st and 98th British BMI and WC centiles showed moderate agreement (weighted kappa = 0.58). Overweight was more frequent in Brazilian than British children: 15.1 % of girls and 20.1 % of boys were above the 91st percentile of the 1990 BMI for age British references. About one-quarter (22.0 % of girls and 26.9 % of boys) exceeded the 91st percentile of WC British references. The present data could be used to compare WC in children in other populations and may serve as a baseline for future studies of temporal trends in WC in Brazil.

Motivational effects of 12-week moderately restrictive diets with or without special attention to the Glycaemic Index of foods.

Low glycaemic index (GI) diets may facilitate weight loss via behavioural and/or endocrine mechanisms. This study investigated whether the outcomes of the Weight Watchers POINTS Weight-Loss System could be improved by encouraging dieters to select low GI, high-carbohydrate foods. Ninety-six women (age 20-72 years; BMI 25-40 kg/m2) were recruited as they started the Weight Watchers POINTS programme for 12 weeks. Weekly classes were randomized so that seven (forty-five women) followed the regular programme while seven others (fifty-one women) followed a revised programme encouraging the selection of low GI foods. Anthropometric and biochemical parameters were measured before and after the 12-week diets. Participants rated hunger and desire to eat using visual analogue scales on 1 d per week, several times per d. Attrition was the same in both groups (32 v. 30 %), as well as many benefits (5 % weight loss, decreases in insulinaemia and blood lipids, waist and hip circumferences, blood pressure). Hunger and desire to eat were rated consistently lower in the low GI group over the 12-week diet. Group differences in subjective sensations were especially large in the afternoon. The 12-week weight management yielded many significant anthropometric and biochemical benefits that were not improved by encouraging dieters to select low GI foods. The subjective benefits (lower hunger and desire to eat) of the low GI diet may be a worthwhile contribution to the motivation of dieters that might affect adherence to the diet over the long term.

Association between melanocortin-4 receptor mutations and eating behaviors in obese patients: a case–control study

Melanocortin-4 receptor (MC4R) gene mutations are involved in the leptin-melanocortin pathways that control food intake. The effect of these mutations on eating behavior phenotypes is still debated. To determine the association between functional MC4R mutations and eating behaviors, dietary intake and physical activity, we sequenced the MC4R gene in 4653 obese adults. Among them, 19 adults carriers of functional MC4R mutation were matched on age, sex and body mass index with two randomly-paired controls without MC4R mutation (n=57). We found that eating behaviors and physical activity did not differ between groups. In particular, cases were not at increased risk of binge eating disorders. Subjects carriers of MC4R mutation reported a higher proportion of dietary carbohydrates intakes (43.2±7.1 and 39.2±8.1% of total energy intake, respectively, P=0.048) and a lower proportion of dietary lipids (34.3±6.7 and 38.5±6.7% of total energy intake, respectively, P=0.018). In conclusion, mutation carriers differ from controls by a higher consumption of carbohydrates counterbalanced by a lower consumption of lipids expressed as percentage of total energy intake. However, functional MC4R mutations do not have a higher risk of compulsive eating contrary to what was previously suggested.