Anne-Marie Dalix

Non food-related environmental stimuli induce increased meal intake in healthy women: comparison of television viewing versus listening to a recorded story in laboratory settings

The objective of the present study, performed under laboratory conditions, was to assess the impact of two non food-related environmental stimuli (television and auditory stimulus) on meal intake. Normal weight women (N = 48) ate lunch in the laboratory once a week for four weeks. All lunches were identical and included popular traditional foods, of which participants could eat ad libitum. The first and last lunches were eaten in the absence of the environmental stimuli (control conditions); in the other two tests, presented in random order, subjects ate while either watching television or listening to a recorded story. Energy intakes were determined for each meal, as were ratings of hunger, satiety and meal palatability. Subjects filled out the Three Factor Eating Questionnaire at the end of the meal series. Meal size was significantly larger in the presence of both environmental stimuli than in both control conditions (+11.6%, 280 kJ, p < 0.01). Television viewing induced a significant stimulation of intake, equal to, but not greater than the effect of the auditory stimulus. Ratings of hunger, satiety, and palatability were not significantly different between conditions, despite the differences in intake. These results suggest that environmental, non food-related stimuli could stimulate intake regardless of hunger-satiety or palatability conditions. Environmental stimulation of eating should be tested in other populations, eg subjects with weight control problems, and other conditions, e.g. free-living.

Palatability and intake relationships in free-living humans: characterization and independence of influence in North Americans

In order to investigate palatability influences on the ad lib eating behavior of free-living humans, 564 participants were paid to maintain food intake diaries for 7 days. They recorded their intake along with a global rating of the palatability of the entire meal on a seven-point scale. It was found that most meals that are self-selected are palatable and that only 9.3% are rated as unpalatable. Meals that were highest in palatability were 44% larger than meals that were low in palatability, but palatability only accounted for around 4% of the variance in meal sizes. Multiple regression demonstrated that palatability appears to act on intake independent of the levels of other influential factors. These results were very similar to those observed for the French and suggest that palatability operates similarly on intake regardless of culture. Palatability appears to be an influence on the amounts ingested by free-living humans in their natural environments but appears to be only one of many influential factors and accounts for only a small proportion of the variance in intake.

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.

Culture and meal patterns: A comparison of the food intake of free-living American, Dutch, and French students

In order to establish the generalizability or cultural specificity of the factors that influence the ad libitum eating patterns of free-living humans, the eating behaviors of 26 French, 140 American, and 50 Dutch university students were measured with a diet diary technique. Marked cultural differences were present in the amounts, composition, diurnal rhythm, and pattern of intake. In comparison to the French and the Americans, the Dutch ate considerably more overall and ingested a large number of small meals separated by relatively short intervals. They ate with more other people present, for a longer duration at a slower rate, with larger deprivation ratios and smaller satiety ratios, and had more food remaining in their stomachs at the beginning of the meal. Even with these differences the univariate or multivariate correlations between meal size or the aftermeal interval with the time of day, the number of people present, the subjective state of hunger, the stomach contents, and the premeal interval were quite similar between nationalities. These relationships varied in magnitude especially when hunger self-ratings, the time of day, or the aftermeal interval were involved, but, the directions of the relationships were in all cases the same. These results suggest that, although cultural effects permeate the eating pattern, many of the social, psychological and physical variables that influence intake are similar across cultures.

Palatability and intake relationships in free-living humans: measurement and characterization in the French.

To investigate palatability influences on the ad lib eating behavior of free-living humans, 54 French participants were paid to maintain food intake diaries for four 7-day periods. They recorded their intake along with palatability ratings, on a seven-point scale, of each individual item eaten and also a global rating of the palatability of the entire meal. Higher levels of palatability were found to be related to larger meal sizes, durations, and deprivation ratios, smaller satiety ratios, greater hunger, and lower depression and anxiety. The global palatability rating was found to be superior to individual item palatability ratings as a measure of the palatability of the meal. Although palatability was found to have fairly large effects on intake, it accounted for less than 2% of the variance. It was concluded that, in the natural environment, there are a large number of other powerful variables present that add variance. In addition, people tend to self-select only a restricted range of highly palatable foods. As a result, in the natural environment, the influence of palatability on intake is limited.

Human responses to five concentrations of sucrose in a dairy product: immediate and delayed palatability effects

Preferences for five sucrose concentrations (0, 5, 10, 20 and 40 g of sugar per 100 g of plain yogurt) were assessed in men and women by brief-exposure sensory evaluation tests and intake tests. Ten ad-libitum yogurt intake tests (with each concentration presented twice) and two sensory evaluation tests (one before and one after the series of intake tests) were conducted. Food intake in the 24 h after each test was estimated using dietary records. Sweetness intensity ratings did not change as a function of test condition. In contrast, hedonic ratings in sensory evaluation tests were more closely correlated to actual intake in experienced than in naive subjects. In intake tests the preferred sucrose concentrations were 5 and 10%. Food intake in the first few hours after yogurt intake was significantly greater on 10%-sucrose days relative to the other concentration days in men only. Although there was a tendency to eat more over the 24 h after consumption of the preferred yogurts, this effect was not statistically significant. Total daily intake, including the calories in the yogurts, was greater on intake days than on sensory evaluation days, indicating that the energy derived from the yogurts was not compensated for by a decrease in subsequent intake.

Monosodium glutamate affects mealtime food selection in diabetic patients.

Lunch intake was followed in 31 matched pairs of hospitalized diabetic patients over four consecutive days. Pairs of patients were matched for type and duration of diabetes, gender, age and body mass index. Lunches were composed of appetizer, meat, vegetables, starch, cheese, bread and dessert; water, coffee, tea and lemon were available. One patient per pair was randomly ascribed to the experimental group and was served vegetable and starch dishes added with 0.6% monosodium glutamate (MSG). Lunch intake was measured by weighing amounts served and left-overs. Patients in the experimental group ingested more starch food than their matched controls, and less lemon juice and yogurt. However, the total energy load at lunch was not different between groups. This effect on meal time food selection replicates earlier observations made on elderly persons. It is suggested that manipulating palatability of various foods within a meal, and especially by using MSG, is an efficient way to affect food selection in the meal, without inducing hyperphagia.

Influence of dietary restraint and environmental factors on meal size in normal-weight women. A laboratory study

In a previous study, we observed that the level of dietary restraint in normal-weight women moderated the stimulating effect of environmental stimuli on meal intake. The present study was designed to confirm and extend this observation. The influence of factors previously shown to affect meal size was investigated: presence of other people, television viewing and listening to radio. Two groups of 20 women were recruited, characterized by high versus low restraint. They participated in five standardised ad libitum lunches, under controlled laboratory conditions: subjects ate alone; in groups; listening to a detective story on the radio; watching television (no food cues); watching food advertisements on television. Lunches had identical menu (main dish and dessert) and were scheduled at 1-week intervals. Visual analogue scales were used to assess hunger, fullness and test-meal palatability. Repeated measures ANOVAs revealed no significant main effect of level of restraint and no interaction with meal conditions. Energy and main dish intakes were lower in the group meal condition than in the other four, which did not significantly differ. Group meals were followed by less intense fullness than the other conditions. These observations raise questions about the factors affecting social influence at meal times; gender, level of acquaintance and inhibitory norm are discussed. Our results also suggest that the intake stimulating effects of various external sources of distraction at meal time could vary in different populations.

The effect of Type I diabetes on the eating patterns of free-living French: a diet diary study.

In order to investigate the changes produced by Type I diabetes on the ad libitum eating behavior of free-living humans, 56 French participants with diabetes and 28 healthy controls were paid to maintain detailed food intake diaries for four 7-day periods. The participants with diabetes ate more protein and more frequent meals, ate slightly later and with fewer other people, were less hungry, thirsty, and depressed, but more elated than the healthy participants. Responses to social facilitation, the diurnal rhythm, subjective hunger, the palatability of the food, and the weekend were not affected by the presence of diabetes. The participants with diabetes had significantly larger correlations and regression coefficients for the relationship between meal size and the duration of the before-meal interval. The relationship between meal size and the after-meal interval was strong and positive in all participants. The recorded behavioral characteristics of diabetics may, in part, be accounted for by the nutritional education that is provided as an integral part of treatment. Based upon these results, it was theorized that the glucose regulatory system is an influence on intake, but only one of many that are responsible for the coordination, control, and regulation of nutrient intake in free-living humans.