Alfred W. Pennington

Pennington in his employment with duPont, was asked to protect their executive team from heart disease. Weight reduction was one key objective. Pennington himself struggled with the same issue. His initial efforts to reduce the weight of duPont executives failed too.

In 1944 he heard a lecture by Dr Blake Donaldson, who in 1961 would write the short book Strong Medicine to explain his methods. Donaldson worked for the cardiologist Robert Halsey, in the beginning of his career, and he was charged with helping their patients to lose weight. Without success of course. In 1919, reading about Inuit diets and talking to anthropologists at the American Museum of Natural History, who told him that prehistoric humans lived almost exclusively on the fattest meat they could kill. had become very interested in diets that were entirely meat based. [It makes good sense when you know that Donaldson was also a keen hunter.] Vilhjalmur Stefansson, about this time was also active promoting the Inuit diet. Over the next 20 years tried to improve the diet by trial and error. Donaldson was well aware of success/failure the Bellevue Experiment in 1929.

Pennington was intrigued. He tried the method Donaldson had suggested, and it worked well for himself. Then he tried it with 20 DuPont executives. With success. They lost an average nearly two pounds a week, eating three meals a day 6 ounces of lean meat and 2 ounces of fat (cooked weight) [170gm of lean meat and 57gm of Fat.]. He allowed one small serving of carbohydrate a day. The small number of executives who lost the least weight, found that even this small addition of carbohydrates could prevent weight loss.

In 1950 the success of this diet was explained in Holiday Magazine as an "all eat-all-you-want reducing diet."

In April, 1951, Pennington wrote a six page article about his diet for the Delaware State Medical Journal.
There is a photographic copy of that article here.

Here are the key points:
The body has it's own elaborate system of heat and energy regulation.
All the energy your body uses is derived from the food you eat.
The laws of thermodynamics must apply to the human body, but simple calculations of energy in v energy out, always fail, so the body is more complex than we know.
The body is dynamic, tissues are building up and breaking down, fat is being stored and then removed from storage. Carbohydrates are oxidised into pyruvic acid, then used immediately for energy, stored in limited amounts as glycogen, or returned to the liver and converted into fatty acids.

In contrast, the ability of the body to oxidise fats is unlimited. Blood triglycerides are readily used as energy in the absence of excess blood glucose, body fat is turned into ketones by the liver. Researcher scientist W. C. Stadie estimates that ketones as fuel can deliver 8000 to 12000 calories a day. ["The Intermediary Metabolism of Fatty Acids" (1945)]
The point is that your carbohydrate metabolism is limited, while your ability to burn fat is essentially unlimited. The low level of carbohydrate (glucose) in the blood allows the body to begin burning fats.

The body knows to store excess energy from carbohydrates as fat, preparing for the time when food is scarce. Insulin is a growth and fat storage hormone. Eating carbohydrate stimulates the production of insulin. When insulin is low, fat burning can begin. Alternatively, when insulin is high fat storage is enabled.

A Diet For Obesity

After eight hours sleep, go out immediately and walk for 30 minutes.

Cook a substantial meal as much as you like, lean meat and animal fat, in the ratio of nine ounces of lean meat to three ounces of fat (cooked weight). [255gm of lean meat and 85gm of Fat.] Season with black pepper, paprika lemon or parsley. Don't use any salt. OFH: This is more than most people can eat.

Eat the same meal three times a day. You can have black coffee tot tea, but without sugar or saccharine. Drink water. The success of the diet depends on having enough fat.

Once a day at one of your three meals you can add a single ordinary portion of: white potatoes, boiled rice, half a grapefruit, a banana or pear, or some raspberries or blueberries. Those who don't continue to lose weight, need to reduce or eliminate this source of carbohydrates.

You MUST NOT eat: bread, flour, salt, sugar or alcohol.

Twenty overweight men, lost an average of 21 pounds each [9.5 kg] in three and a half months on this diet.

Other Publications

The Use of Fat in a Weight Reducing Diet

Published in the Delaware State Medical Journal, April 1951.

A Reorientation on Obesity

Pennington presented a paper on this topic at the Postgraduate Assembly, Boston, October 29, 1952.

By this time even Prof Mark Hegsted at Harvard University was interested.

Treatment of obesity: Developments of the past 150 years

A paper published in March, 1954

These papers are still available to subscribers. Online someone referred to the fact that long before Dr Robert Atkins there were others who had 'discovered' a low carbohydrate diet. Dr. Andreas Eenfeldt, MD the founder and CEO of Diet Doctor,responded.

[July 24 2013] "Yes, there are better ways to do it. Not bad for a sixty-years-old plan though. And I'm happy that there's been SOME progress since 1953! ;)"

Pennington got a polite reception at a Harvard Obesity Symposium, that prompted more publicity, and then a reaction from the American Medical Association. JAMA took the position that calorie restriction was the only legitimate way to induce weight loss. This stance was also adopted by the Lancet in the UK.

Many clinical doctors were disappointed. They claimed that the diet worked in most cases and that Pennington's work was dismissed too easily. Raymond Greene the British endrocrinologist, now a Yale, wrote, "Pennington's idea of cutting out the carbohydrate but allowing plenty of protein and fat in the diet works excellently."

The first dietitians to support Pennington's diet were Margaret Ohlson and Charlotte Young. Young had struggled for years with her weight, at one stage weighing 260 pounds. She was dissatisfied with calorie restrictive diets.

Ohlson began research with four of her laboratory staff, initially trying a calorie restrictive diet, 1200 calories a day for 15 weeks. in theory the weight loss should have been 22 pounds each. The result, zero,, six, seven and seventeen pounds. The women complained about being hungry and lacking energy.

Then she tried Pennington's method, but not trusting him she also tried to calorie restrict the diet, 1400 calories a day. This time seven overweight young women for 16 weeks. "Without exception the low carbohydrate reducing diet produced success," Ohlson said. The average weight loss was three pounds a week, and the subjects felt well and never complained of hunger. Not only that, the subjects added muscle, and improved their dress sizes more than expected.

A Cornell University, Charlotte Young worked in a similar way with Pennington's Diet, but she also calorie restricted. Her first study group of 16 overweight women ran for ten weeks. Weight loss was between nine pounds and 26 pounds, with the average weight loss at nearly 2 pounds a week. At the time the flu was spreading on campus, but these women remained healthy, they reported a sense of well-being, that their skin had improved, and that they were never hungry.

Many other clinics continued to be report success using the Pennington Diet, but the tide of nutrition practice was moving in a different direction.