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

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Milk and dairy products in human nutrition
legumes, other dietary fibre sources, seafood rich in long-chain PUFAs) with a relatively
lower intake of energy dense processed and fried foods, and sugar sweetened
beverages; and to avoid consumption of large portion sizes. Moderate consumption
of dairy products and lean meats and poultry can also be an important part of recommended
food-based dietary guidelines. Maintaining recommended dietary patterns,
appropriate energy intake and adequate physical activity levels are critical to prevent
unhealthy weight levels (i.e. overweight and obesity)” (FAO and WHO, 2010).
4.6.2 Association between dairy intake and weight status
Nutritional studies examined use a wide range of outcome and exposure measures
making it very difficult to compare results of studies. Sample sizes and the type of
dairy analysed vary and some studies do not control for energy restriction. If adjustments
are not made for total energy intake, the energy from dairy food in excess of
total daily energy requirement could confound the impact of dairy on obesity risk.
Additionally, direct comparison of prevalence rates of overweight and obesity is
difficult as different countries use different methodology, criteria and growth references
in classifying overweight and obesity.
FAO and WHO (2010) concluded that “there was convincing evidence that
energy balance is critical to maintaining healthy body weight and ensuring optimal
nutrient intakes, regardless of macronutrient distribution of energy as percent total
fat and percent total carbohydrates”. As it was not possible “to determine at a
probable or convincing level the causal relationship of excess energy and unhealthy
weight gain”, the current recommendation for a maximum intake level of 30–35 percent
of energy from fat was considered prudent. “There was agreement among the
experts that in populations with inadequate total energy intake, such as seen in
many developing regions, dietary fats are an important macronutrient to increase
energy intake to more appropriate levels” (FAO and WHO, 2010).
Epidemiological studies on dairy and obesity can be broadly categorized as
those that assess the positive effect of dairy on weight gain and those that examine
the protective role of dairy (particularly calcium) against weight gain. Louie et al.
(2011) recently systematically reviewed prospective cohort studies that assessed the
longitudinal relationship between dairy and obesity. Out of 19 studies, eight (three
involving children and five involving adults) showed a protective association of
dairy intake against weight gain, seven found no impact on weight, one reported a
significant protective association among overweight men, one reported an increased
risk of weight gain among children with a high milk intake, and two studies reported
both an increased and decreased risk of weight gain, depending on the dairy food
type. Low-fat products were not found to be any more beneficial to weight status
than whole milk or full-fat products. Thus, although there is some indication of a
protective effect of dairy on weight, it is not conclusive, suggesting that if such an
effect exists the magnitude is likely to be small (Louie et al., 2011). Additionally,
a recent systematic review of 16 studies reported that “the observational evidence
does not support the hypothesis that dairy fat or high fat dairy foods contribute to
obesity and suggests that high fat dairy consumption within typical dietary patterns
is inversely associated with obesity risk” (Kratz, Baars and Guyenet, 2012).
In a study of 14 618 adults in the United States, Beydoun et al. (2008) found
a positive association between cheese consumption and obesity and a negative