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

Chapter 4 – Milk and dairy products as part of the diet 139
Some studies suggest that moderately increasing protein intake, while controlling
total energy intake may improve body composition and improve body-weight
maintenance (Westerterp-Plantenga, 2003; Paddon-Jones et al., 2008; Abou-Samra
et al., 2011). The potential positive outcomes associated with increased protein
are thought to be due to lower energy intake associated with increased satiety and
increased thermogenesis. Findings of studies of the impact of dairy proteins, whey
and casein, on satiety are inconclusive (Abou-Samra et al., 2011). The effects of
whey protein, such as reduction of short-term food intake and increased satiety
have been mostly observed in short-term experiments when whey is consumed
in much larger amounts than that found in usual serving sizes of dairy products
(Luhovyy, Akhavan and Anderson, 2007). Inconsistencies in the studies may be
attributed to the study design, subject sample or the different physical properties of
the proteins used. Additionally, dairy proteins are consumed in food form (Anderson
et al., 2011) and as such, “despite the suggestion of acute or transient benefits
attributable to specific proteins, any such effect may be masked by the concomitant
ingestion of a mixture of proteins and other macronutrients in a normal mixed diet”
(Paddon-Jones et al., 2008).
There is a need for well-designed long-term intervention studies that clearly
define the primary outcome (body-weight changes or measures in adiposity) to
confirm if dairy products can increase weight loss and/or improve weight maintenance
(Harvey-Berino et al., 2005; Major et al., 2008; Van Loan, 2009; Zemel, 2009;
Dougkas et al., 2011).
4.7 Dairy intake, metabolic syndrome and type 2 diabetes
Metabolic syndrome (MetS) describes a cluster of metabolic abnormalities that are
risk factors for CVD and type 2 diabetes mellitus (T2DM), including abdominal
obesity, hypertension, elevated fasting glucose, elevated triglycerides and low
high-density lipoprotein (HDL) cholesterol (Mokdad et al., 2001). Worldwide,
197 million people have impaired glucose tolerance due to obesity and MetS, and it
is estimated that by 2025 this number will rise to 420 million (Hossain, Kawar and
Nahas, 2007). Recommendations for preventing and managing MetS include reducing
obesity, increasing physical activity and effecting dietary change 27 (Grundy et
al., 2004). According to the International Diabetes Federation, primary management
of MetS includes promoting healthy lifestyle with energy restriction (to achieve a
5–10 percent loss of body weight in the first year), moderate increases in physical
activity, a reduction in total and saturated fat intake, increased fibre intake and
reduced salt intake (Alberti, Zimmet and Shaw, 2006). In addition, whenever possible,
a normal BMI and/or normal waist circumference should be a long-term target
of lifestyle interventions. However, Feldeisen and Tucker (2007) suggest that a diet
low in saturated fat (rather than low in total fat), trans fat and cholesterol, and a
balanced carbohydrate intake rich in dietary fibre, fruit and vegetables, and inclusion
of low-fat dairy products may be most beneficial for reducing the risk of the MetS.
27 These recommended dietary guidelines include low intakes of saturated fats, trans fats and
cholesterol; reduced consumption of simple sugars; and increased intakes of fruits, vegetables
and whole grains.