I’m a big believer in eating natural and unprocessed foods, which means basing the diets on foodstuffs such as meat, fish, eggs, nuts, vegetables and some fruit. However, I am not averse to having some dairy products in the diet, in particular full-fat plain yoghurt. With a few nuts and berries chucked in, I reckon this represents a decent breakfast or dessert for those who eat such things. I often don’t eat breakfast, but when I do, it’s almost always something cooked (eggs with smoked salmon, omelette) or the yoghurt mix described here.
There’s a general concern that dairy products are to be avoided on account of their offering of saturated fat. I have no personal fear here on the basis that there are practically no links between saturated fat and heart disease, and eating less saturated fat has not been shown to have broad benefits for health.
Another common concern about fat in dairy is that this will rapidly add to the fat held in the body (i.e. fatty foods are fattening). A recent study reviewed the studies in which dairy products were emphasised in the diet and measures of body composition assessed [1]. Overall, the results found that, if anything, inclusion dairy products led to:
1. reduction in fat mass
2. increase in lean body mass (muscle)
3. reduced waist circumference
All these things are, generally speaking, to be desired.
It has been suggested that the apparent beneficial effects dairy products on body weight relates to their calcium content. Consumption of calcium has been shown to paradoxically lower calcium level within fat cells, and this accelerates the process of lipolysis (breakdown of fat) [2]. There is considerable evidence linking higher intakes of calcium and dairy products with reduced body fatness [3].
It has been suggested that not just calcium, but other chemical constituents in dairy products somehow assist fat loss. There is evidence that supplementing the diet with dairy products (yoghurt) can enhance fat loss, including abdominal fat [4,5]. In one of these studies [4], the group supplementing with yoghurt saw their waist circumferences shrink by an average of about 4.0 cm, compared to a reduction of only about 0.5 cm in individuals supplementing with calcium alone.
While dairy products have theoretically fattening potential due to their influence on insulin, the evidence suggests their incorporation in the diet is unlikely to be a barrier to weight loss, and may in fact help here.
There’s also concern, justified I think, that dairy products are a common cause of ‘food intolerance’ issues. Raw dairy products appear to be better tolerated than pasteurised, and I also find in practice that yoghurt is better tolerated than milk. This might have something to do with the fact that the bacteria deployed in the fermentation process that forms yoghurt partially digest milk proteins [6,7], making them easier to digest and therefore less problematic. An added benefit from yoghurt is that it contains less lactose than milk, and is generally better tolerated by individuals who are lactose intolerant.
References:
1. Abargouei AS, et al. Effect of dairy consumption on weight and body composition in adults: a systematic review and meta-analysis of randomized controlled clinical trials. International Journal of Obesity 2012;36,1485–1493
2. Zemel MB, et al. Regulation of adiposity by dietary calcium. FASEB Journal 2000;14:1132-1138
3. Teegarden D. Calcium intake and reduction of fat mass. J Nutr 2003;133:249S–251S
4. Zemel MB, et al. Dairy augmentation of total and central fat loss in obese subjects. Int J Obes (Lond). 2005;29(4):391-7
5. Zemel MB, et al. Effects of calcium and dairy on body composition and weight loss in African-American adults. Obesity Research 2005;13(7):1218-25
6. Loones A. Transformation of milk components during yogurt fermentation. In: Chandan RC (ed). Yoghurt: nutritional and health properties. Mc Clean VA: National Yoghurt Association 1989:95-114
7. Beshkova DM, et al. Production of amino acids by yoghurt bacteria. Biotechnol Prog 1998;14:963-965