1. Global public healthcare is challenged by alarming rates of obesity incidences, how sever is the situation today in Canada and how can this be linked to local (yogurt) consumption trends?
The prevalence of adult overweight and obesity has increased drastically since the three last decades and is now reaching 60% of the adult population. This has not only important health consequences in adult (e.g. hypertension, type II diabetes and cardiovascular diseases) but also impact on the future generation. Children who have an obese parent are more likely to become overweight or obese adults and thus more likely to suffer from these health consequences. Latest Canadian survey indicated that more than one out of three children are overweight or obese. While the causes of obesity are complex and multi-factorial, unhealthy eating habits have been implicated as one important of the causative factors. This includes a reduced consumption of traditional foods such as dairy (including yogurt) and increased consumption of highly processed foods and beverages. According to the Canadian Community Health Survey, most children and adolescents do not meet the daily dairy recommendations.
2. In your new research on yogurt, body weight and metabolic profile, why do you focus on children/adolescents, susceptible to obesity? And do you have recommendations to improve yogurt intake in this young target group?
Most observational studies in adults have shown an inverse association between dairy consumption and body weight. Despite some beneficial, albeit inconsistent, effects of dairy products on weight-related and metabolic health in adults, few studies have been conducted in children and adolescents, particularly concerning the specific effect of yogurt consumption on weight variables and metabolic profiles. Moreover, the few studies conducted in children/adolescents are inconsistent. Their rapid growth and pubertal changes make it difficult to ensure that the changes are due to yogurt and other dairy products and not developmental changes and other factors may be implicated in the relationship. The inconsistent findings suggest a possible association between dairy intake and body weight but that hidden factors may be implicated in the relationship between yogurt/dairy intakes and body weight in children and youth. Genetics susceptibility to obesity may potentially be one factor. One cross-sectional study found that only milk consumption and parental obesity remained significant predictors of child BMI z-scores, indicating that both factors independently influenced the child’s body weight (Barba et al. 2005). This information is important as parental obesity implies genetic susceptibility to obesity in children, which may moderate the dairy products-body weight relationship. Body weight status could represent another independent factor moderating the yogurt/dairy and body weight association. In line with this, we also observed that overweight and obese adults appear to obtain the most weight-related benefits from increased yogurt intake.
We think that more research related to the impact on yogurt consumption on body weight and metabolic health will help health professional to recognize the value of yogurt, in addition to a healthy diet and lifestyle, particularly in children and adolescents at risk for obesity and to promote yogurt consumption as a healthy food choice for reasons that are in addition to nutrient content including better weight management and metabolic profile. Research in this area could also help to increase public awareness of the importance of yogurt as part of a healthy diet and that consumption of yogurt should increase to at least comply with dairy recommendations.
Reference: Barba G, Troiano E, Russo P, et al. (2005) Inverse association between body mass and frequency of milk consumption in children. Br J Nutr 93: 15-9.
3. As yogurt consumption is associated with less weight gain over time, which specific mechanisms contribute to this correlation and how differs the preventive effect of yogurt, compared to other dairy foods?
Several potential mechanisms have been suggested to explain the association between dairy consumption and indicators of body weight and composition. Although milk and yogurt are similar in their nutrient composition, yogurt possesses unique properties that may provide additional health benefits on body weight management and metabolic profile. These include:
- high nutrient density (e.g. proteins, calcium, magnesium, phosphorus, vitamin B12);
- high digestibility and bioavailability of nutrients;
- lactic acid bacteria content which may affect gut microbiota, its food form and the replacement of less healthy foods;
- high quality dairy proteins content (whey protein and casein) which increase satiety, reduce energy intake, contribute to glycemic control and maintain skeletal muscle mass in weight loss.
In addition to yogurt composition, calcium has also been shown to play a role in body weight management by correcting the calcium content in adipose tissue and preventing the cascade of events leading to lipogenesis (fat synthesis) and inhibition of lipolysis (fat degradation and utilisation). Calcium has also been shown to reduces energy absorption in the gut and increases fecal fat excretion.
Reference: Albala C, Ebbeling CB, Cifuentes M, et al. (2008) Effects of replacing the habitual consumption of sugar-sweetened beverages with milk in Chilean children. Am J Clin Nutr 88: 605-11.
4. According to your previous research, can you describe how yogurt consumption is associated with healthy eating and other lifestyle habits?
Studies from our research group showed that an increase in milk intake was associated with decreased weight gain in adults over 6 years (Drapeau et al., 2004) and low calcium consumption in participants from the QFS was associated increased adiposity in women (Jacqmain et al., 2003). Among different mechanisms implicated in this inverse association between dairy consumption and body weight, diet quality could be one of them. Accordingly, we showed in two different cohorts (QFS and INFOGEN) that adults yogurt consumers have lower body weights, improved metabolic health parameters and higher diet quality compared with non-consumers (Hubert et al., 2015 and Pahahi et al., unpublished). More specifically, yogurt consumption was a significant contributor to the Prudent dietary pattern (reflecting healthy eating pattern) along with other healthy items such as fruits, vegetables, and nuts. Also, yogurt consumption was associated with lower anthropometric indicators and a more beneficial cardio-metabolic risk profile in overweight/obese individuals. These results suggest that yogurt is a good source of several macronutrients, micronutrients and bioactive peptides that may help to maintain metabolic well-being and improve body weight control. It also seems to be a good indicator of a healthy diet, which can also contribute to these positive effects.