A systematic review of the use of the Satiety Quotient.

The satiating efficiency of food has been increasingly quantified using the Satiety Quotient (SQ). The SQ integrates both the energy content of food ingested during a meal and the associated change in appetite sensations. This systematic review examines the available evidence regarding its methodological use and clinical utility. A literature search was conducted in six databases considering studies from 1900 to April 2020 that used SQ in adults, adolescents and children. All study designs were included. From the initial 495 references found, fifty-two were included. Of the studies included, thirty-three were acute studies (twenty-nine in adults and four in adolescents) and nineteen were longitudinal studies in adults. A high methodological heterogeneity in the application of the SQ was observed between studies. Five main utilisations of the SQ were identified: its association with (i) energy intake; (ii) anthropometric variables; (iii) energy expenditure/physical activity; (iv) sleep quality and quantity and (v) to classify individuals by their satiety responsiveness (i.e. low and high satiety phenotypes). Altogether, the studies suggest the SQ as an interesting clinical tool regarding the satiety responsiveness to a meal and its changes in responses to weight loss in adults. The SQ might be a reliable clinical indicator in adults when it comes to both obesity prevention and treatment. There is a need for more standardised use of the SQ in addition to further studies to investigate its validity in different contexts and populations, especially among children and adolescents.

Physical Activity and Sedentary Behavior of Elderly Populations during Confinement: Results from the FRENCH COVID-19 ONAPS Survey.

Introduction: A national confinement was imposed in France in March 2020 during 55 days to prevent the spread of the virus and protect vulnerable people such as older individuals. This study aimed to describe the movement behaviors, and their determinants, of elderly people (≥ 65 years) during the confinement.Methods: An online survey was conducted from April 1st, 2020 to May 6th, 2020 by the National Observatory for Physical Activity and Sedentary behaviors. This study compared the level of physical activity (PA), sitting and screen time before and during the confinement and identified the impact of initial PA, sedentary profiles of the participants and housing conditions.Results: 1,178 people were included in this study. Reaching PA recommendations before lock-down was associated with the change in PA level during lock-down (p < .001). Besides, geographic location was associated with the change in PA, sitting time and screen time during lock-down (respectively p = .03, p = .02, p = .02).Conclusion: This study confirm the negative impact of confinement on senior movement behaviors, whether or not they met with public health recommendations prior to the pandemic. The housing conditions of older people must be also taken into future public health policies.

Post-moderate-intensity exercise energy replacement does not reduce subsequent appetite and energy intake in adolescents with obesity.

Exercise modifies energy intake (EI) in adolescents with obesity, but whether this is mediated by the exercise-induced energy deficit remains unknown. The present study examined the effect of exercise with and without dietary replacement of the exercise energy expenditure on appetite, EI and food reward in adolescents with obesity. Fourteen 12-15-year-old adolescents with obesity (eight girls; Tanner 3-4; BMI 34·8 (sd 5·7) kg/m2; BMI z score 2·3 (sd 0·4)) randomly completed three experimental conditions: (i) rest control (CON); (ii) 30-min cycling (EX) and (iii) 30-min cycling with dietary energy replacement (EX + R). Ad libitum EI was assessed at lunch and dinner, and food reward (Leeds Food Preference Questionnaire) before and after lunch. Appetite was assessed at regular intervals. Lunch, evening and total EI (excluding the post-exercise snack in EX - R) were similar across conditions. Lunch and total EI including the post-exercise snack in EX + R were higher in EX - R than CON and EX; EX and CON were similar. Total relative EI was lower in EX (6284 (sd 2042) kJ) compared with CON (7167 (sd 2218) kJ; P < 0·05) and higher in EX + R (7736 (sd 2033) kJ) compared with CON (P < 0·001). Appetite and satiety quotients did not differ across conditions (P ≥ 0·10). Pre-meal explicit liking for fat was lower in EX compared with CON and EX + R (P = 0·05). There was time by condition interaction between EX and CON for explicit wanting and liking for fat (P = 0·01). Despite similar appetite and EI, adolescents with obesity do not adapt their post-exercise food intake to account for immediate dietary replacement of the exercise-induced energy deficit, favouring a short-term positive energy balance.

Satiety responsiveness but not food reward is modified in response to an acute bout of low versus high intensity exercise in healthy adults.

To compare the effect of iso-caloric low and high intensity exercises on Satiety Quotient and Food Reward in response to a fixed meal in healthy young adults. Anthropometric measurements, body composition (BIA), aerobic capacity (VO2 max) and food preferences were assessed in 19 healthy normal-weight young adults (21 ±â€¯0.5 years old, 10 men). They randomly completed 3 experimental sessions: i) control session without exercise (CON); ii) High Intensity exercise session (HIE); iii) Low intensity exercise session (LIE). Thirty minutes after exercise or rest, then received a fixed lunch. Food reward (Leeds Food Preference Questionnaire) was assessed before and after the meal. Appetite sensations were assessed at regular intervals, SQ was calculated from the lunch meal and self-reported food intake was collected for the rest of the day. Mean body weight was 66.7 ±â€¯9.2 kg, body mass index was 22.3 ±â€¯2.9 kg/m2 and FM% was 18.7 ±â€¯6.8%. Appetite feelings did not differ between conditions and were not affected by exercise. SQ for satiety was not different between conditions. SQ hunger on CON was significantly higher than on LIE and HIE (p ≤ 0.05) with no difference between exercise conditions. SQ for desire to eat was significantly higher on CON versus HIE (p ≤ 0.01) with no differences between CON and LIE and between exercise sessions. SQ PFC was significantly lower on HIE compared with CON (p = 0.02) with no differences between LIE and CON and between LIE and HIE. Food reward was not significantly different between the three condition as well as self-reported total food and macronutrient intake for the rest of the days. Acute exercise, depending on its intensity, might affect the satiating response to food intake in healthy adults, without altering food reward.

Effect of exercise-meal timing on energy intake, appetite and food reward in adolescents with obesity: The TIMEX study.

The present study manipulated the delay between exercise and test meal to investigate its effect on energy intake, appetite sensations and food reward in adolescents with obesity. Fifteen adolescents with obesity randomly completed 3 experimental sessions: i) rest without exercise (CON); ii) 30 min of exercise 180 min before lunch (EX-180); iii) 30 min of exercise 60 min before lunch (EX-60). Ad libitum energy intake was assessed at lunch and dinner, and food reward (LFPQ) assessed before and after lunch. Appetite sensations were assessed at regular intervals. Absolute energy intake was not different between conditions despite a 14.4% lower intake in EX-60 relative to CON. Lunch relative energy intake (REI: energy intake - exercise-induced energy expenditure) was higher in CON compared with EX-60 (p < 0.001). Lunch fat intake was lower in EX-60 compared with CON (p = 0.01) and EX-180(p = 0.02). Pre-lunch hunger in CON was lower than EX-180 (p = 0.02). Pre-lunch prospective food consumption and desire to eat were lower in CON compared with both exercise conditions (p = 0.001). A significant condition effect was found for explicit liking for high-fat relative to low-fat foods before lunch (p = 0.03) with EX-60 being significantly lower than EX-180 (p = 0.001). The nutritional and food reward adaptations to exercise might be dependent on the timing of exercise, which is of importance to optimize its effect on energy balance in adolescents with obesity. CLINICAL TRIAL REFERENCE: NCT03807609.

Effect of the COVID-19 lockdown on physical activity and sedentary behaviors in French children and adolescents: New results from the ONAPS national survey.

INTRODUCTION: In France March 14, 2020 a national lockdown was imposed in France for 55 days to prevent the spread of COVID-19 and all schools were closed. This study aimed to investigate the effects of home confinement as a result of  lockdown on the activity (physical activity and sedentary behaviors), and their determinants, on French children (6-10 years) and adolescents (11-17 years). METHODS: The National Observatory for Physical Activity and Sedentary behaviors launched an online survey from April 1st, to May 6th, 2020 using popular social networks and websites. It compared the level of physical activity (PA), sitting and screen time before and during the lockdown and identified the impact of the initial PA (active vs. inactive), sedentary (high vs. low) profiles of the participants and their housing conditions. RESULTS: 6,491 children were included in this study. Initially active children and adolescents decreased their PA more than those initially inactive (p>0.001), while those who met the sitting time recommendations increased more their sitting time during lockdown (p<0.001). The same applied to screen time (p<0.001). Living in an urban environment was associated with a decrease in PA (p<0.001), an increase in sitting time (p<0.001) and children's screen time (p=0.002) during lockdown. CONCLUSION: This study showed the deleterious effects of confinement caused by lockdown on physical activity and sedentary behaviors. Housing conditions were associated with lifestyle behaviors over this period of lockdown. Future public health policies should consider these results.

Influence of phase transformation on stress evolution during growth of metal thin films on silicon.

In situ stress measurements during two-dimensional growth of low mobility metal films on amorphous Si were used to demonstrate the impact of interface reactivity and phase transformation on stress evolution. Using Mo1-xSix films as examples, the results show that the tensile stress rise, which develops after the film has become crystalline, is correlated with an increase in lateral grain size. The origin of the tensile stress is attributed to the volume change resulting from the alloy crystallization, which occurs at a concentration-dependent critical thickness.

Appetite control and exercise: Does the timing of exercise play a role?

The prevention and management of chronic diseases, particularly overweight and obesity, relies on multidisciplinary strategies mainly combining dietary approaches with physical activity. Recently, the timing of exercise (time of the day as well as delay/position relative to a meal) has been suggested as an important parameter to consider when prescribing physical activity. Some studies have for instance shown the interest of the timing of exercise on the glycemia, sleep and body composition regulation. However, the impact of exercise-timing on appetite control and energy intake remains unclear. This is why, the present paper questions whether physical exercise, depending on its timing during the day and related to a meal, can affect energy intake, appetite sensations and food reward. Although evidences remain actually limited, exercising during the morning; and particularly close to lunch, might have a better impact on overall energy balance through reduced subsequent energy intake, without leading to compensatory intakes at the following meals. Importantly, dealing with the timing of exercise to optimize energy balance (and affect energy intake and appetite) does not only require to consider its time during the day (morning vs. afternoon or evening), but also and maybe mainly its order/position (pre vs. post) and delay regarding meals. While the actual literature remains limited in this area, the present paper tends to highlight the importance of considering the timing of exercise to optimize our impact on the overall energy balance, and to encourage the elaboration of further studies to better understand and determine the potential effect of this timing of exercise, in order to find the best combination between the different exercise characteristics, intensity, duration, modality, to empower these effects.