In my book Twenty-First Century Nutrition and Family Health
I studied the proportions of protein, fat and carbohydrate that made up traditional diets before modern food production and distribution changed the way we eat, when obesity, coronary heart disease and type 2 diabetes were virtually unknown. I came the conclusion that the ideal proportions for typical "Western" people who are not particularly energetic are 25:45:30 repectively, measured as percentages of our total calorie intake. So what does a diet like this look like in practice?
The corresponding ratios of 14:38.5:47.5* that are typical of an average Briton's diet are very different from those I recommend. The average Briton eats relatively far too little protein and far too much carbohydrate! So what I did was to prepare a full menu (three complete meals plus drinks and some small snacks) for three days, in such a way that the the ratio of total calories obrtained from protein, fat and carbohydrate came to exactly 25:45:30 respectively. And as a result I concluded a healthy diet should look like this.
· A healthy diet contains only a little food that is high in starch. Although this menu plan provided 30% of the total calories from carbohydrates, over the three days it included only 4½ slices of bread per person, 25gm of flour, half a large potato, no breakfast cereals other than a small bowl of porridge, and no cakes, biscuits, rice, pasta, crisps or starchy snacks at all. Adding more of such foods would inevitably increase the percentage of calories from carbohydrates to above 30%.
· A healthy diet contains little or no added sugar or sugary foods and drinks, and of course no alcohol. The menu plan allowed only a rounded teaspoonful of sugar and a level teaspoon of reduced sugar jam over the 3 days. It would be better still to have omitted the sugar altogether.
· Although many people on this diet would consider that they were eating well, particularly at breakfast, it provided only 1,823 kilocalories a day. This may mean that the British government’s recommended daily calorie intakes of 2,000 kcals for women and 2,500 kcals for men are too high, which would help to explain why so many people in the U.K. are overweight. Alternatively it may be that with a diet richer in protein one doesn’t need to consume so many calories. In the end you can discover the number of calories you need to maintain a constant weight only by trial and error, since it depends on your personal height, metabolism and lifestyle. Too heavy: eat less; too light: eat more!
· In order to obtain 25% of calories from protein it may be necessary to take a protein supplement. In my experimental menu plan, 5% of the protein calories were provided by one drink of 25gm of whey protein. Whey protein is sold as a plain or flavoured powder that makes a milky drink when mixed with water. Tubs of it are sold in health food shops at a cost of around 60p per drink, so it is fairly expensive.
· Meat, fish and seafood were clearly the main sources of protein in food, so vegetarians would have to eat plenty of fish and seafood, or huge quantities of eggs and dairy products, or gigantic quantities of nuts and mushrooms (including soya products and Quorn), in order to obtain 25% of their calories from protein. Their only alternative, so far as I know, would be to consume substantial amounts of protein supplements such as whey protein, if that is permissible.
· A healthy diet includes nourishing, cooked breakfasts. This is because eggs and other protein-rich foods delay hunger pangs longer than carbohydrate-rich foods such as breakfast cereals with the same number of calories. If you don’t feel hungry you won’t be tempted so much to go snack hunting.
· A healthy diet includes fruit and vegetables. Ideally we should eat a fruit and five vegetables a day.
· In my book, each ingredient is assigned a ‘calorie index’, which shows the best foods to eat to increase your protein consumption relative to your carbohydrate consumption. The highest values were for cod, lamb’s liver and chicken. The lowest values were for sugar, fruit and fruit juice. The calorie indices for starchy foods such as rice, spaghetti, couscous and milk chocolate digestive biscuits are –0.8, –0.7, –0.6 and –0.5 respectively, all low values indicating that it is best not to eat too much of them.
How much would such a diet cost? I carefully costed the 3-day menu, mainly from Tesco’s website and based on mid-range prices and normal sizes. The total cost, including all the suggested snacks, and of course the ‘essential’ three drinks of coffee a day, worked out at £33.72 per person per week, or nearly £68 a week for two people. (£68 is about US$110 or Aus$124.) This included the cost of minor items such as herbs, some rather expensive out-of-season blackberries and runner beans that found their way on to the menu, and the whey protein drink. It did not allow for possible savings on the more expensive items like meat and fish, which might be bought more cheaply in your local market or on offer in a supermarket, nor any savings that could be made on the bulk purchases of goods, home-grown produce and home-made bread and yogurt.
£33.72 is admittedly more than the average British adult spends each week on food and drink. The Office for National Statistics reports that the average household in the U.K. spent £53.40 a week on food and non-alcoholic drink in 2009-2011.** With an average number of 2.28 inhabitants per household, that works out at £23.40 per head per week. This includes children, who wouldn’t eat so much, so the average expenditure per adult would be rather more than this, particularly in the south-east where we live and the average household expenditure was £57.80 rather than £53.40. The average cost per adult in the south-east might therefore be around £27, as compared with £33.72 for a much healthier diet.
However the same report stated that the average U.K. household spent £11.70 a week on alcoholic drinks, tobacco and narcotics, with the majority of that on alcohol. If that is representative of your family you could always switch that expenditure to pay for a healthy diet and thus be far healthier at no extra cost!
* Family Food 2011. U.K. Government Department for the Environment, Food and Rural Affairs.
** Family Spending, 2012. Chapter 5: Weekly household expenditure, an analysis of the regions of England and countries of the United Kingdom. Office for National Statistics, Feb 2013.