The Body Mass Index (BMI), is the most convenient indicator of chronic undernutrition. As noted previously, a desirable BMI would be in the range 20 -25, but low BMI values also impact negatively on health. In India, individuals with a BMI lower than 16 had a mortality rate of 32.3/1000/year compared with 12.1/1000/year in individuals with a BMI greater than 18.5. Figure 5.4 shows the relationship between low BMI’s and fathers not working because of illness. Women suffer even more than men in this regard.
Figure 5.4. Relationship between BMI and fathers not working due to illness in Bangladesh. (Adapted from references 49 and 50)
Whilst it is true, that high fat intakes can lead to obesity, fat intake should be regulated to maintain a desirable BMI. Moreover, fat intakes that are desirable for adults may be totally inappropriate for infants and growing children. Fears that fat consumption in children may lay the foundation for cardiovascular disease, cancer and other degenerative diseases in adulthood, may have been premature, as there is no convincing scientific data to support this claim. The fact is, children need more fat in their diets than adults.51,52 Vegan vegetarians on a whole food low fat diet should monitor their children to ensure that they receive adequate quantities of fat in the diet. This can be achieved by selecting whole foods with a high fat content such as nuts, seeds, avocado, olives and high fat legumes. Spreads and nut or seed creams and milk can be used liberally by children whereas adults may need to restrict the intake of large quantities of these foods. The key lies in monitoring ones BMI, and using foods with a high fat content to maintain body weight at an optimum. Children on vegan diets need not and should not look like undernourished children.
At a recent symposium of the American Institute of Nutrition, the following point of view found substantive support: 1) Providing adequate energy and nutrients to ensure adequate growth and development remains the most important consideration in the nutrition of children.
2) During preschool and childhood years, nutritious food choices should not be eliminated or restricted because of fat content. During early adolescence, and energy intake adequate to sustain growth should be emphasised, with gradual lowering of fat intake. Once linear growth has stopped, fat intake at the level recommended for adults is appropriate. 3) Food patterns that emphasise variety and complex carbohydrates and include low-fat choices are appropriate for children. 4) Physical activity and healthy eating are important lifestyle habits for children. They conclude that from the age of two until the end of linear growth there should be a transition from the high-fat diet of infancy to one with no more than 30% of calories from fat and no more than 10% of energy from saturated fat.52