Most healthy people I know would eat cereal or fruit for breakfast. This gives complex carbohydrates for long-term energy. But I have a physical job as a gardener and I know if I rely on this intake I鈥檒l be ravenous by 10 am. On the other hand, if I have eggs, I鈥檒l be fine until midday. Clearly I need protein, but that shouldn鈥檛 give me energy. What is going on and is this common?
鈥� It may be that your hunter-gatherer ancestry is responsible for the favourable response to your morning serving of eggs. In the course of human evolution we have become physiologically adapted to the diet that prevailed for most of that time, that of a hunter-gatherer. This diet is assumed to have been dominated by lean meats, fruits and vegetables. Cereal grains, on the other hand, are a relatively new addition to our diet, having found their place on the dinner table with the onset of the agricultural revolution only 10,000 years ago.
It has been suggested that our pre-agricultural diet is the best way to support healthy physiological function, including improved energy production and appetite control. One of the characteristics of this diet is a low 鈥済lycaemic load鈥�, which means glucose is released slowly into the blood as food is digested. Another is a higher level of lean protein than that eaten by modern humans. These characteristics are found in your eggs, whereas most breakfast cereals and fruit have higher glycaemic loads and lower protein content.
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The low glycaemic load of your meal may help to stabilise your blood sugar level, sharp drops of which precede an increase in appetite. The protein is also a strong inducer of cholecystokinin, a gut-derived satiating hormone. Carbohydrate is not the only source of energy in our diets. The fat in your breakfast eggs provides approximately double the energy of carbohydrate, albeit in a slow-release form.
Benjamin Brown, Technical research officer, Health World, Northgate, Queensland, Australia