A diet consisting of carbohydrates, water, and salts would support life for a short time only. Practically no advantage would be gained by substituting fats for carbohydrates. On the other hand, a diet of proteins, salts, and water would support life for a much longer period, but even in this case the actual duration of life on such a diet would be short. If we take a protein and a non-nitrogenous principle together in the diet, an enormous advantage is gained, especially if the two are present in the necessary proportions. For the very best forms of diet, the three great classes of foods must all be represented, namely proteins, carbohydrates and fats, and even then a variety in the form of protein chosen is beneficial.
Comment: I find this table fascinating - the first time I've seen a balanced broken down into 'grains' of carbon or nitrogen. A grain is about 6.479891 × 10-5 kilograms. Whether we think in terms of mass of Nitrogen or Carbon when we organise our dinner menu is another question but there is clearly a push to use the scientific method to explain how to balance a diet. Would be great to see Nigella Lawson explain to us the content of her dishes in this way ;-)
If a man attempted to live on meat alone he would have to eat 75 ounces of meat to get 4800 grains of carbon, while 29 ounces would be sufficient to supply 300 grains of nitrogen. This is an example of an unbalanced diet. Similarly if we had to live on bread alone we would require 54 ounces to supply the necessary nitrogen, but only 40 ounces would supply the 4800 grains of carbon. There would obviously be a great waste in a diet of this kind, but by having mixed foods it is possible to have an economical diet, without any waste at all. For instance, 11 ounces of meat and 34 ounces of bread would supply the required carbon and nitrogen without any excess or deficiency.
Comment: According to this, 300 grams of meat (11 ounces roughly) would be enough for us on a daily basis.... compare this with what you get in an original recipe meal at KFC. Surely, eating a steak is well over the above requirements. I'm sure there are new studies that have been done to determine precisely how much we really need to eat of each food type. One thing is for sure: you can't just copy another person's diet. Everyone has different lifestyles and metabolic rates. Therefore, diet programmes cannot be right unless you get supervised by a proper dietician or doctor. The next post will be on meals (a short one!).
Comment: the idea of a balanced diet is certainly engrained in concepts like 'five-fruits/veg-a-day' or the way meals are prepared for proper exercise programmes (certainly with more protein). However, it's not clear whether young adults and teenagers of this age have been properly taught about the concept of a balanced diet and how this is necessary for a healthy lifestyle.
Obviously, the actual quantity of food that is necessary will vary greatly according to the climate, the age, the sex, and the amount and nature of the work that has to be done. For example, a large amount of all kinds of food, but more especially heat-producing food, is required in cold climates and for laborious occupations. Also, women are said to generally need one-tenth less food than men; but if such is really the case, it is probably only due to the fact that their work is of a much lighter character than men's work. The proper food for children will be discussed at the end of this chapter.
Comment: there is some truth to the fact that the right quantity of food depends on several external/natural factors - and many tend to ignore this nowadays. The lack of medical evidence behind the claim that women should eat less is very clear and, as we know today, is clearly supported by measures of metabolic rates for men and women. What was merely 'probable' is now certain thanks to advances in human physiology research.
It is found that the average individual loses by the lungs, kidneys, skins and bowels about 300 grains of nitrogen and 4800 grains of carbon in twenty-four hours. This loss must be made good by means of the food supplied. If too much nitrogen or too much carbon is supplied we say that the diet is wasteful or unbalanced. The above quantities of carbon and nitrogen are supplied in a diet of the following composition:-
| Ounces | Grains of Nitrogen | Grains of Carbon. | |
| Proteins | 4.5 | 310 | 1040 |
| Fats | 3 | 0 | 1040 |
| Carbohydrates | 14 | 0 | 2720 |
| Salts | 1 | 0 | 0 |
| Total | 22.4 | 310 | 4800 |
If a man attempted to live on meat alone he would have to eat 75 ounces of meat to get 4800 grains of carbon, while 29 ounces would be sufficient to supply 300 grains of nitrogen. This is an example of an unbalanced diet. Similarly if we had to live on bread alone we would require 54 ounces to supply the necessary nitrogen, but only 40 ounces would supply the 4800 grains of carbon. There would obviously be a great waste in a diet of this kind, but by having mixed foods it is possible to have an economical diet, without any waste at all. For instance, 11 ounces of meat and 34 ounces of bread would supply the required carbon and nitrogen without any excess or deficiency.
Comment: According to this, 300 grams of meat (11 ounces roughly) would be enough for us on a daily basis.... compare this with what you get in an original recipe meal at KFC. Surely, eating a steak is well over the above requirements. I'm sure there are new studies that have been done to determine precisely how much we really need to eat of each food type. One thing is for sure: you can't just copy another person's diet. Everyone has different lifestyles and metabolic rates. Therefore, diet programmes cannot be right unless you get supervised by a proper dietician or doctor. The next post will be on meals (a short one!).
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