Volume 1

First report / Committee on Nutrition in the Colonial Empire.

  • Great Britain. Committee on Nutrition in the Colonial Empire.
Date:
1939
Catalogue details

Licence: Public Domain Mark

Credit: First report / Committee on Nutrition in the Colonial Empire. Source: Wellcome Collection.

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    loss of nutritive values, as for example in diarrhoea. The requirements of particular food factors may be accentuated by disease or some phase of it, as in the case of fever or other diseases in which there is excessive blood destruction. 50. Again, while there is at present little precise knowledge on the subject, the nutritional requirements of an individual may, it seems, vary appreciably according to his race and the climate in which he lives. Thus in a tropical country where sunshine is abundant the requirements of vitamin D should be less than in a temperate country in winter where sunshine is comparatively rare.* In a hot country a smaller consumption of fats will be required than in a cold country. Possibly also through long custom one race may have adapted themselves to some special feature in the diet which economically is easiest to obtain. Most Colonial dietaries, for instance, being largely vegetarian are bulky relative to their nutritive value and it may be that people who for generations have been used to vegetarian diets can tolerate a greater bulk than others. 51. Another factor for which allowance must be made is the interaction of various foodstuffs on one another. Much attention is now being given to the effects upon one another of the various components of a diet. Thus, as already stated, when proteins from different sources are fed as a mixture, their biological value may be greater than their values when fed singly. Again the ratio of calcium to phosphorus in the diet is impor- tant; also, no doubt, the amount of calcium in the presence of limited amounts of vitamin D. The disposition of “‘ fibre ”’ in foods of vegetable origin is probably of more importance than the total amount as estimated by chemical means. A similar consideration holds for the nutritional value of different meats and “‘ cuts ’’ of meat in relation to the amount and distri- bution of connective tissue. Traces of inorganic elements in foods may also be of importance in determining their realisable value for the diet. The vitamin Bz requirements of the body seem to be determined to some extent by the Calorie value of the food or of the carbohydrate portion of it. The capacity of different foods for forming acids or bases in the tissues of the body is another factor of outstanding importance, and it seems that the contribution made by a foodstuff to oxidation and reduc- tion processes in the body may also have to be taken into account in assessing its value. 52. Another aspect of dietary studies is the possible action of toxic substances in foods. In Western countries control has been * It would, however, be rash to be too dogmatic on this subject. Rickets are known to exist even in the most sunny climates, e.g., in Iraq and Aden. The anti-rachitic quality of the sunshine may not be entirely dependent on the strength of the sun’s rays. Moreover where purdah exists or the sun is too strong exposure to the sun may be avoided. Again, a summer’s day in a temperate climate is much longer than a tropical day.