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

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Milk and dairy products in human nutrition
increases in only one of the countries (Ruel, 2003). Allen et al. (1992) looked at
longitudinal data from 67 Mexican children aged 18–30 months and found that
diets of taller children contained more animal products, including milk, than did
diets of shorter children.
School-aged children
Intervention studies
The classic Boyd Orr study (or Carnegie survey) was carried out in the beginning
of the last century among 1 343 mainly working class families, and examined the
effects of supplementing the diets of 5- to 14-year-old Scottish children at school
with whole milk, skimmed milk or biscuits that contained an equivalent amount of
energy, compared with a control group receiving no supplements (Orr, 1928). Those
receiving either type of milk gained an average of 20 percent more height in seven
months (Orr, 1928), but only children who continued to receive milk supplements
sustained higher rates of growth (Leighton and Clark, 1929). Because this study was
conducted in pre-war Britain, it is plausible that some degree of malnutrition was
present in the children at the onset of the study (Hoppe, Mølgaard and Michaelsen,
2006), and the effect of milk on growth may have occurred because of a correction
of nutrient deficiencies. Hoppe, Mølgaard and Michaelsen (2006) also refer to work
carried out by Spies and co-workers in the United States on a selected group of 82
children with chronic nutritive and growth failure (Spies et al., 1959). The threeyear
study, initiated in 1945, looked at the effect of daily supplementation with
either whole or non-fat dried milk on the growth in the intervention group compared
with a control group. The children receiving the milk supplements gained an
average of 1.23 cm more height than the control group during the supplementation
period (Hoppe, Mølgaard and Michaelsen, 2006).
A limited number of RCT studies are currently available. One RCT was carried
out on 33 children in New Guinea aged 6–15 years old who had very low protein
diets. The majority of the children were below the third percentile in height at
the beginning of the study even though the Bundi people of New Guinea have
a reliable supply of food throughout the year from their staple crops of taro and
sweet potato (Lampl, Johnston and Malcolm, 1978). Three groups of children were
given diets supplemented with skim milk powder (75 g/day), margarine with an
equivalent amount of energy or extra servings of taro and sweet potatoes over a
13-week period, and compared with a control group who received no supplementary
food. The linear growth of children receiving the skim milk supplements was
nearly twice as fast as that of children in the other groups (Lampl, Johnston and
Malcolm, 1978).
An RCT was carried out in rural Viet Nam, in a region where the prevalence of
stunting was 50 percent. Schoolchildren (7–8 years old) were provided with 500 ml
of unfortified milk on school days for six months (Lien do et al., 2009). The control
group received no supplementation. Height gain was 0.4 cm greater and weight gain
0.5 kg greater in the milk intervention group than in the non-intervention control
group, although these differences were not significant. However, both weight-forage
and height-for-age significantly improved over the six months that milk was
provided, and as a consequence the incidence of underweight and stunting dropped
by roughly 10 percent.