Milk-and-Dairy-Products-in-Human-Nutrition-FAO

Chapter 4 – Milk and dairy products as part of the diet 137
association between yoghurt and obesity, possibly due to the higher energy density
in cheese compared with other dairy products. The lack of a relationship between
milk or dairy-product intake and weight gain is also supported by Mozaffarian et
al. (2011). This large-scale investigation involved three separate cohorts (Nurses’
Health Study, Nurses’ Health Study II and the Health Professionals Follow-up
Study) totalling 120 877 women and men in the United States and examined the
relationship between multiple lifestyle changes (diet, physical activity, television
watching, alcohol use, sleep duration and cigarette smoking) and long-term weight
gain. The authors assessed a range of dietary factors including fruits, vegetables,
whole and refined grains, potatoes, potato crisps, whole-fat and low-fat dairy
products, sugar-sweetened beverages, sweets and desserts, processed meats, unprocessed
red meats and fried foods. They reported that “eating more or less of any
one food or beverage may change the total amount of energy consumed, but the
magnitude of associated weight gain varied for specific foods and beverages. The
analysis showed relatively neutral associations between change in the consumption
of most dairy foods and weight gains” (Mozaffarian et al., 2011). All liquids except
milk were positively associated with weight gain and no significant differences were
observed for low-fat and skim milk versus whole-fat milk. Yoghurt consumption
was associated with less weight gain in all three cohorts; however the mechanism for
this finding is not clear (Mozaffarian et al., 2011).
A recent systematic review of RCTs found that increased dairy intake without
energy restriction may not lead to significant change in weight, whereas dairy
consumption in energy-restricted diets result in a greater reduction of weight and
fat mass and gain in lean body mass (Abargouei et al., 2012). In controlled feeding
studies in adults and adolescents, dairy did not affect energy balance (Van Loan et
al., 2011; Weaver et al., 2011).
Dairy consumption and childhood obesity
Whether dairy consumption in childhood has an etiologic role in the development
of obesity in later life is an open area of discussion (Moore et al., 2006). IGF-1 levels
may be indicative of risk of obesity as IGF-1 may be one of the factors involved
in fat-cell formation. This is supported by some observations of high IGF-1 levels
in obese children. However, not all clinical evidence supports this and normal concentrations
of IGF-1 have also been reported in obese children (Hoppe, Mølgaard
and Michaelsen, 2006). IGF-1 may further contribute to obesity development as
it suppresses the secretion of growth hormone, which is related to lean body mass
(Hoppe, Mølgaard and Michaelsen, 2006; Dougkas et al., 2011). The impact of
milk protein intake on body composition has not been fully elucidated. Intake of
dairy protein in infancy may increase the risk of excess weight gain in childhood
(Hoppe et al., 2004; Gunther et al., 2007). However, it is also important to consider
that body weight includes fat, muscle and bone mass and the association between
dairy protein and weight gain in children may be related to the increase in non-fat
mass during growth and development (Cadogan et al., 1997; Spence, Cifelli and
Miller, 2011).
In a cohort study of 12 829 American children between the ages 9 and 14 years,
Berkey et al. (2005) found that the BMI of children who drank more than three
servings of milk per day increased more than that those who drank less milk as a