How many calories must a man wolf down?

Dr Paul Clayton’s Health Newsletter Spring 2015

The answer, my friend, may surprise you. According to the UK’s Advertising Standards Agency (ASA), it would be extremely difficult for consumers to devise a 600-calorie diet providing 100% of vitamin and mineral RDAs. What geniuses …

… because the literature clearly shows that a minimum of 750 calories a day is needed, and that only works if the diet is highly specialised and made up of fish and molluscs combined with portions of quark, spinach, mushrooms, rye bread, strawberries, nuts, raisins and sunflower seeds. In any conventional diet, even 2,000 calories cannot provide all the recognised vitamins and minerals (FAO).

If you then extend the nutritional requirements to include recommended levels of other key micro- and phyto-nutrients such as the poly-phenols, the 1-3, 1-6 beta glucans, prebiotic fibres, xanthophylls and carotenoids, this cannot be achieved in under 3,300 calories, and that too requires a highly specialised diet (IFBB Oxford, Out of the Fire ’14).

This may seem an unfeasibly large number of calories but is easily consumed by physically active people such as athletes and our hardworking mid-Victorian ancestors. For today’s urbanised and sedentary folk, however, fortified foods and/or supplements have become essential.


FAO Annex Three. The scientific basis for diet, nutrition and health relationships.


Out of the Fire. Paul Clayton, PharmacoNutrition Press, Hong Kong 2014.