Our favourite charity shop is sending books out again and This Slimming Business, arrived recently. Published in 1958, it was the first book by Professor John Yudkin MA MD PhD MRCP FRIC, Professor of Nutrition and Dietetics, Queen Elizabeth College, University of London.

Professor Yudkin (1910-1995) firmly believed that excess sugar in the diet, could be partially responsible, for both obesity and coronary thrombosis, which started rising, when rationing ended. Many older people seemed to believe that the British wartime diet was healthier. ” People weren’t fat ” they assert, as if weight is the only indicator of health.

Sugar was rationed in Britain, throughout World War Two. In April 1945, sugar was restricted to 8oz (227g) of sugar per week, with a further 1lb (0.45kg) or 2lbs (0.91kg) marmalade or 1lb (0.45kg) jam/preserves per month. Additionally, 12oz (340g) of sweets (candy) per month were allowed.

Ancel Keys, who was neither a medical doctor, nor a nutritionist believed that saturated fat caused heart disease. As the inventor of K rations for US armed forces, he had influence. Even though his research was flawed, and he cherry-picked data to fit his theory, Keys caused the USA and therefore most of the world, to demonise fat.

Professor Yudkin’s book starts by asking readers to assess whether they are overweight, by use of a height-weight chart. Unlike other charts, his doesn’t allow extra weight with age.

Then he moves into discussing why being overweight isn’t ideal before writing about overeating and the Calories In, Calories Theory which Gary Taubes has explored. Calories were developed to measure how much energy it took to boil a known quantity of water. Humans don’t burn energy at a uniform rate and our individual metabolism slows as we age. Whether you measure food by calories or grams, different types of food aren’t processed by the body, in the exact same way. When a cola manufacturer claims that a calorie is a calorie, it is being disingenuous.

At this point in the book, Professor Yudkin maintains that in order to lose weight, we must create an energy deficiency ie expend more calories than we take in. If you exercise and feel hungry. it’s because the body wants to replenish the calories lost and hunger makes people eat (if they can). There are a couple of graphs on this.

Professor Yudkin includes what he calls a ‘nutritional interlude’ and this is useful. He debunks some myths about the nutritional value of foods. For example, a person would have to eat 48lbs of honey to get the recommended daily dose of thiamine ((Vitamin B1).

Yudkin divides food into four groups:

Group 1: milk and cheese
Group 2: meat, fish, eggs
Group 3: fruit, vegetables
Group 4: butter, margarine

Yudkin maintains that we should have ” two reasonable helpings” from each group, per day. He adds that if enough Group 1 milk or cheese or both, are consumed, that adding foods from Group 2 are not necessary, that day.

Yudkin suggests that we should buy food on the basis of cost of nutrition. He gives some tables, which show for example, that half a pint of milk will provide 40% of the calcium needed, and that 2 ounces (56.6 grams) of peas will provide 50% of the daily requirement for vitamin C.

In the next two chapters, Yudkin demolishes slimming aids such as sweeteners, and fad diets. This is followed by reasons why slimmers feel miserable and hungry on a low fat diet and why a low protein diet is a bad idea.

Finally, Chapter Ten arrives, entitled ‘We eat too much carbohydrate’. Professor Yudkin theorises that obesity is a result of civilisation ie the switch from hunter gathering to agriculture, based on crops.

In Chapter Eleven ( of thirteen) Yudkin gets to grips with an actual carbohydrate-restricted diet. Yudkin comes up with his own measure of carbohydrate. It really feels like trying to reinvent the wheel. Each carbohydrate unit (CU) is worth 5 grams of carbs. He suggests starting with 15 CUs of carbs a day ie 75 grams and seeing how you get on. To make matters more complicated he uses varying portions of foods eg tablespoon, ounce to provide a CU number for them, with each Carbohydrate Unit being 5 grams of carbs.If the food which you want to eat, contains carbs but isn’t on Professor Yudkin’s list, you’re left somewhat in the lurch.

Professor Yudkin suggests 15 CUs (75g) per day as a starting point. It’s deceiving, because a 2 oz piece of rich iced fruit comes in as 8 CUs, which in reality, is at least 40 grams of carbohydrates. 6 oz cooked spaghetti is 10 CUs or 50g of carbs.

Professor Yudkin gives an example of a day’s meals, totalling 15 CUs (75g carbs)


Half a grapefruit
Eggs and bacon
One slice, bread and butter
Tea or coffee


Tea or coffee


Stewed beef
Brussels sprouts
2 starch-reduced rolls, butter
Fresh fruit salad with cream


Tea with one sweet biscuit


Grilled fish
One medium potato
Starch reduced rolls, butter
Tea or coffee



This seems way more than 75 grams of carbs to me. It’s also a quaint idea, that someone would have such a large lunch in the middle of the day, unless they were coming home for lunch or eating out, retired or working from home.

Professor Yudkin ends his book with some psych stuff about going out to supper and managing your expectations of weight loss.

The book is quite simple to read. Well laid out, progresses logically. It reads like an avuncular professor, dictating to his secretary over tea and biscuits in his study. I wouldn’t rely on the carb content of food or recommended dietary intakes, as being accurate, because science has moved on in 62 years. The drawings are amusing, and it must surely be a collectable book.

However there are some take aways:

  1. You won’t stick to a diet which you hate
  2. A diet should be able to accommodate a fairly normal way of eating, for social occasions
  3. Carbohydrates are not an essential food group
  4. Buy food by looking at the relation between the nutrition you will get and the price.

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