No abstract

Emerging literature highlights the need to incorporate physical activity into every strategy intended to prevent weight gain as well as to maintain weight loss over time. Furthermore, physical activity should be part of any plan to lose weight. The stimulus of exercise provides valuable metabolic adaptations that improve energy and macronutrient balance regulation. A tight coupling between energy intake and energy expenditure has been documented at high levels of physical exercise, suggesting that exercise may improve appetite control. The regular practice of physical activity has also been reported to reduce the risk of stress-induced weight gain. A more personalized approach is recommended when planning exercise programs in a clinical weight loss setting in order to limit the compensatory changes associated to exercise-induced weight loss. With modern environment promoting overeating and sedentary behavior, there is an urgent need for a concerted action including legislative measures to promote healthy active living in order to curb the current epidemic of chronic diseases.

A growing body of evidence suggests an inverse relationship between calcium and vitamin D status and dairy food intake and the development of the insulin resistance syndrome (IRS) and type 2 diabetes mellitus (t2DM). Observational studies show a consistent inverse association between dairy intake and the prevalence of IRS and t2DM. In a systematic review of the observational evidence, the odds for developing the IRS was 0.71 (95% CI, 0,57-0.89) for the highest dairy intake (3-4 servings/d) vs. the lowest intake (0.9-1.7 servings/d). Few interventional studies have been conducted to evaluate the effects of dairy food intake on the management of prevention of IRS or t2DM. Intervention studies that have examined the independent effects of dairy intake on specific metabolic components of the IRS including blood pressure and obesigenic parameters have shown favorable effects that support the observational findings albeit the results have been less consistent. Many metabolic and dietary factors appear to influence the degree to which dairy affects IRS metabolic parameters including calcium and vitamin D intake status, BMI, ethnicity and age. Overall, the intake of low-fat dairy products is a feature of a healthy dietary pattern which has been shown to contribute to a significant extent to the prevention of IRS.

Dairy products provide Ca and protein which may facilitate appetite control. Conversely, weight loss is known to increase the motivation to eat. This randomised controlled trial verified the influence of milk supplementation on appetite markers during weight loss. Low Ca consumer women participated in a 6-month energy-restricted programme (22508 kJ/d or 2600 kcal/d) and received either a milk supplementation (1000 mg Ca/d) or an isoenergetic placebo (n 13 and 12, respectively). Fasting appetite sensations were assessed by visual analogue scales. Anthropometric parameters and fasting plasma concentrations of glucose, insulin, leptin, ghrelin and cortisol were measured as well. Both groups showed a significant weight loss (P,0·0001). In the milksupplemented group, a time £ treatment interaction effect showed that weight loss with milk supplementation induced a smaller increase in desire to eat and hunger (P,0·05). Unlike the placebo group, the milk-supplemented group showed a lower than predicted decrease in fullness (2 17·1 v. 2 8·8; 212·7 v. 3·3 mm, P,0·05, measured v. predicted values, respectively). Even after adjustment for fat mass loss, changes in ghrelin concentration predicted those in desire to eat (r 0·56, P,0·01), hunger (r 0·45, P,0·05) and fullness (r 20·40, P, 0·05). However, the study did not show a between-group difference in the change in ghrelin concentration in response to the intervention. These results show that milk supplementation attenuates the orexigenic effect of body weight loss. Trial registration code: ClinicalTrials.gov NTC00729170.Key words: Milk: Appetite: Dairy products: Weight loss: Visual analogue scales: Obesity Body weight loss is generally recommended to decrease the risk and the severity of obesity-related comorbidities (1) . However, benefits that accompany weight reduction are often of short to medium term. This can particularly be explained by the occurrence of undesired side effects that result from fat mass loss and promote weight regain (2 -4) . For instance, weight-reducing programmes have been shown to increase the motivation to eat (5 -7) and, in the long run, this change can predict weight relapse (7) . A novel area of investigation consists of finding some satiating agents that may attenuate the increase in hunger induced by body weight loss.Some data suggest that Ca consumption could play a considerable role in the maintenance of a healthy body weight. Under free-living conditions, a negative association between daily Ca intake and adiposity markers has been observed (8) . Moreover, dietary Ca deficiency was recently reported to induce a greater increase in the risk of obesity than high fat intake or sedentariness (9) . Growing evidence also suggests that increasing Ca intake decreases the risk of obesity (10 -12) .Some mechanisms have been proposed to explain the potential influence of Ca consumption on body weight and fat mass. As reviewed by Major et al.