Sylvie Rousset

Daily protein intakes and eating patterns in young and elderly French

An adequate level of protein intake is required to limit the gradual body protein loss observed during ageing. Different factors (cohort age, sex, life conditions) may modify protein intake and distribution. However the precise amounts, as well as their daily distribution which affects protein utilisation and N retention, are unknown in both young and elderly individuals. The hypothesis was tested that protein intake and its distribution over daily meals could be different between the young and elderly. The consumption of six different protein-rich food groups by 292 healthy individuals aged 20-30 and 65-75 years was determined throughout each day for 1 week. The data of the total protein intake and protein intakes at each meal were analysed by ANOVA for each sex separately, using age group as the independent factor. The average protein intake of men was lower in the older age group whilst the opposite trend was seen in women. The distribution of protein intake was different between the two age groups: 56.5 % of the daily protein was eaten at lunch by the elderly but only 47 % (P<0.0001) by the younger subjects. In the elderly subjects, those eating larger amounts consumed a greater proportion of protein-rich foods at dinner than those eating small amounts (30.4 v. 26.2 %, P=0.05). A high level of protein intake was related to a higher meat-product consumption in both the elderly and young individuals. In conclusion, the pattern of protein intake differs significantly between age groups and sexes.

How liked and disliked foods affect time perception.

The purpose of this study was to investigate the influence on time perception of pictures showing liked or disliked foods in comparison with a neutral picture. Healthy adults performed a temporal bisection task in which they had to categorize the presentation duration of pictures (neutral, liked, and disliked foods) as more similar to a short (400 ms) or to a long (1,600 ms) standard duration. The data revealed that the presentation duration of food pictures was underestimated compared with the presentation duration of the neutral picture, and that this underestimation was more marked for the disliked than for the liked food pictures. These results are consistent with the idea that this time underestimation arises from an attentional-bias mechanism. The food pictures, and particularly those depicting disliked food items, distracted attention away from the processing of time.

Intensive exercise: A remedy for childhood obesity?

BACKGROUND Acute exercise can affect the energy intake regulation, which is of major interest in terms of obesity intervention and weight loss. OBJECTIVE To test the hypothesis that intensive exercise can affect the subsequent energy intake and balance in obese adolescents. DESIGN The study was conducted in 2009 and enrolled 12 obese pubertal adolescents ages 14.4±1.5 years old. Two exercise and one sedentary sessions were completed. The first exercise (EX(1)) and sedentary session (SED) were randomly conducted 1 week apart. The second exercise session (EX₂) was conducted following 6 weeks of diet modification and physical activity (3×90 min/week) to produce weight loss. Energy intake was recorded, subjective appetite sensation was evaluated using Visual Analogue Scales and energy expenditure was measured using ActiHerats during EX(1), EX₂ and SED. RESULTS Total energy intake over the awakened period was significantly reduced by 31% and 18% during the EX(1) and EX(2) sessions compared with the SED session, respectively (p<0.01). Energy balance over the awakened period was negative during EX₁, neutral during EX₂ and positive during SED. There was no significant difference in terms of subjective appetite rates between sessions during the awakened hours. CONCLUSIONS Intensive exercise favors a negative energy balance by dually affecting energy expenditure and energy intake without changes in appetite sensations, suggesting that adolescents are not at risk of food frustration.

Emotion and food. Do the emotions expressed on other people's faces affect the desire to eat liked and disliked food products?

The aim of the present study was to test if pleasure, neutrality and disgust expressed by other individuals on a photograph could affect the desire to eat liked or disliked food products. Forty-four men and women were presented with two series of photographs. The first series of photographs was composed of six food photographs: three liked and three disliked food products. The second series consisted of the same photographs presented with eaters expressing three different emotions: disgust, pleasure or neutrality. Results showed that the effect of the presence of an eater, and of emotions expressed by this eater, depended on the food category. For the liked foods, the desire to eat was higher when these foods were presented alone than with an eater expressing neutral emotion. When the eater expressed pleasure, the desire to eat these liked foods did not significantly increase. In contrast, when the eater expressed disgust, the desire to eat them significantly decreased. When the foods were disliked, the influence of the pleasant social context was stronger than for the liked foods. The desire to eat the disliked foods actually increased in the presence of an eater expressing pleasure. On the contrary, the disgust and neutral context had no effect on the desire for disliked foods.

Gender effect on exercise-induced energy intake modification among obese adolescents.

This study examined gender differences in terms of energy intake and appetite feelings after an acute bout of physical exercise among obese adolescents. Seven obese girls and seven obese boys were asked to complete a sedentary and an exercise session in random order, where their food consumption and appetite sensations were assessed. Both boys and girls showed a significant reduction of energy intake on the exercise day without any modification of their appetite readings and no gender differences in food consumption and appetite responses to an acute exercise were noted.

A smartphone-driven methodology for estimating physical activities and energy expenditure in free living conditions

This paper introduces a function dedicated to the estimation of total energy expenditure (TEE) of daily activities based on data from accelerometers integrated into smartphones. The use of mass-market sensors such as accelerometers offers a promising solution for the general public due to the growing smartphone market over the last decade. The TEE estimation function quality was evaluated using data from intensive numerical experiments based, first, on 12 volunteers equipped with a smartphone and two research sensors (Armband and Actiheart) in controlled conditions (CC) and, then, on 30 other volunteers in free-living conditions (FLC). The TEE given by these two sensors in both conditions and estimated from the metabolic equivalent tasks (MET) in CC served as references during the creation and evaluation of the function. The TEE mean gap in absolute value between the function and the three references was 7.0%, 16.4% and 2.7% in CC, and 17.0% and 23.7% according to Armband and Actiheart, respectively, in FLC. This is the first step in the definition of a new feedback mechanism that promotes self-management and daily-efficiency evaluation of physical activity as part of an information system dedicated to the prevention of chronic diseases.

Biological Markers for Meat Tenderness of the Three Main French Beef Breeds Using 2-DE and MS Approach

In order to identify new markers of beef tenderness, a proteomic analysis was performed on Longissimus thoracis muscle to compare two extreme groups in terms of meat tenderness, consisting of 10 animals each of the three main French beef breeds: Blond d’Aquitaine, Charolais, and Limousin. Animals were grouped on the basis of an index combining a tenderness score estimated by a trained panel and mechanical shear force measurement (Warner-Bratzler). The large number of available experimental animals (more than 3,300 young bulls) allowed animals with different meat tenderness but similar main muscle characteristics (fibers, collagen, and lipids) to be chosen. The muscle proteins of the extreme groups considered 24 h after slaughter were analyzed by two-dimensional electrophoresis, statistical analysis, and mass spectrometry. Potential markers of tenderness were suggested for each breed; their marker status varied according to the breed. Only α actin appeared to be a potential marker of tenderness in the three studied breeds. We focused particularly on different abundances of HSP27 and Troponin T fast isoforms between tenderness groups and according to breed.

Protein feeding pattern, casein feeding, or milk-soluble protein feeding did not change the evolution of body composition during a short-term weight loss program

Studies have shown that timing of protein intake, leucine content, and speed of digestion significantly affect postprandial protein utilization. Our aim was to determine if one can spare lean body mass during energy restriction by varying the quality and the timing of protein intake. Obese volunteers followed a 6-wk restricted energy diet. Four groups were compared: casein pulse, casein spread, milk-soluble protein (MSP, = whey) pulse, and MSP spread (n = 10-11 per group). In casein groups, caseins were the only protein source; it was MSP in MSP groups. Proteins were distributed in four meals per day in the proportion 8:80:4:8% in the pulse groups; it was 25:25:25:25% in the spread groups. We measured weight, body composition, nitrogen balance, 3-methylhistidine excretion, perception of hunger, plasma parameters, adipose tissue metabolism, and whole body protein metabolism. Volunteers lost 7.5 ± 0.4 kg of weight, 5.1 ± 0.2 kg of fat, and 2.2 ± 0.2 kg of lean mass, with no difference between groups. In adipose tissue, cell size and mRNA expression of various genes were reduced with no difference between groups. Hunger perception was also never different between groups. In the last week, due to a higher inhibition of protein degradation and despite a lower stimulation of protein synthesis, postprandial balance between whole body protein synthesis and degradation was better with caseins than with MSP. It seems likely that the positive effect of caseins on protein balance occurred only at the end of the experiment.

Hedonism as a predictor of attitudes of young French women towards meat

Iron-deficient young women who are at risk of anaemia should be advised to eat red meat, a good food source of iron. However, red meat is known to elicit negative attitudes among young women, which could lead to low meat consumption. Several factors can contribute to meat attitudes. We therefore hypothesised that a good predictor of attitudes towards meat could be a positive affective component, for example, the pleasure of eating meat. In our study, 77 women with a mean age of 30.5 were surveyed. They were first asked about four hedonism variables (overall, eating, red meat and white meat hedonism) and ethical and nutritional concerns. Secondly, they were asked to express their attitudes of like/dislike towards meat by way of meat pictures, odours and taste. Red meat hedonism was first highly correlated with a liking of raw red and white meat pictures (0.41< or =r< or =0.68), followed by a liking of cooked red and white meat pictures (0.27< or =r< or =0.62). To a lesser extent, red meat hedonism was correlated with a liking of meat odours (0.29< or =r< or =0.38) and beef taste (r=0.32). Finally, red meat hedonism was the best predictor for most of the likings for red and white meat images. Thus, red meat images were pleasant for people who already like meat and did not encourage meat consumption among low meat-eating women.

An acceleration vector variance based method for energy expenditure estimation in real-life environment with a smartphone/smartwatch integration

Investigating the TEE evaluation by predictive functions using smart-{phone, watch}.Using a personalized MET value in regard of the characteristics of participants.New activities classification model to obtain an TEE estimation.Gap less than 4% on both activities classification and TEE.Free Research application available on Google Play. By combining embedded passive sensing technologies from both smartphone and smartwatch, it is possible to obtain a high quality detection of sedentary activities (sitting, reclining postureź), movements (walkingź) and periods of more intense body movements (runningź). Our research encompasses the definition of an energy-saving function for the total energy expenditure (TEE) estimation using accelerometry data. This topic is clearly at the crossroad of both computer science and medical research. The present contribution proposes an intelligent wearable system, which combines the use of two complementary devices: smartphone and smartwatch to collect accelerometry data. Together they can precisely discriminate real-world human sedentary and active behaviors and their duration and estimate energy expenditure in real time and in free-living conditions. The results of the study are expected to help subjects to handle their daily-living physical activity notably for being compliant with the physical activity international guidelines (150min of moderate intensity activity/week). It is also expected that the physical activity feedbacks using these popular devices can prove the effectiveness of such wearable objects to promote individually-adapted healthy behavioral changes. The performance of the proposed function was evaluated by comparing the energy expenditure given by the smartphone and smartwatch with that produced by Armbandź. The mean error of TEE between the proposed function and Armbandź was less than 4% for an average 6h period of daily-living activities. The main theoretical contribution is the definition of a new predictive mathematical function of energy expenditure, which competes with the non-public function used in dedicated costly devices such as Armbandź. In addition, this work demonstrates the potential of wearable technologies.