The Kekwick and Pawan saga began in the early fifties when they were struck with the many studies that suggested that differently composed diets provided differing rates of weight loss. They had read the exciting clinical studies of Dr. Alfred W. Pennington on employees of the Dupont Corporation, as well as German and Scandinavian papers showing success in dieters who restricted carbohydrate. So they did a study on obese subjects and found that those on a 90% protein, and especially on a 90% fat diet lost weight, but when they were given a diet of the same number of calories, 90% of which came from carbohydrate, the subjects did not lose.2
Kekwick and Pawan were so impressed with the potential importance of their unexpected findings that they devoted nearly two decades of their collaboration to learning why and how the theory that all calories are equal seemed to be so patently wrong. They then replicated an animal study of theirs on humans and found the same phenomenon: A low carbohydrate diet of 1000 calories worked well for weight loss and a high carbohydrate 1000 calorie diet took off very little weight.3 They then showed that their subjects did not lose at all on a balanced 2,000 calorie diet, but, when their diet was mainly fat, these same obese subjects could lose even when as much as 2600 calories were given. A typical example was their subject, JB, who lost 9 pounds in 3 weeks on the 2600 calorie low carbohydrate diet, yet not an ounce on the 8 days he was on the balanced 2000 calorie diet.
Skeptics with the calorie is a calorie mindset were in a state of shock and set out to disprove this intellectual bombshell that Kekwick and Pawan had dropped on them.
A spate of studies followed. One, by T. R. E Pilkington and his associates, was published in Lancet in I960.4 But the study dealt with the 1000 calorie level, a level at which nearly everybody loses weight, and only 3 of the subjects in the study were kept as low as 32 grams of carbohydrate, the upper limit of intake to provide a ketogenic diet. But if you look at their data, you’ll see the same striking accelerated weight loss on restricted carbohydrates that Kekwick and Pawan showed, except that the Pilkingtonians blithely eliminated the first 12 days of the low carbohydrate diet from their mathematics, which just happened to be the only way they could make their conclusion that all low calorie diets give the same result fit their data. Their reasoning? They said the low carbohydrate diet causes water loss. How did they know? Unlike Kekwick and Pawan, they did no water balance studies to prove their point. With the ivory tower complacency Galileo’s contemporaries showed when they insisted the Earth could not possibly move around the sun, Pilkington and his associates concluded that their preconceived dogma must certainly be true.
I’m embarrassed for the nutritionists at the AMA who, in their desperate search for ammunition, even cited that study. If you did something like that too often, you could get a reputation as The Gang That Couldn’t Think Straight.
But Kekwick and Pawan stuck by their guns. Their data had shown water loss to be only a small part of the total weight loss. For the next two years, they embarked on a study of mice in a metabolic chamber. By measuring the loss of carbon in the feces and urine, they were able to show that the mice on the high fat diet excreted considerable unused calories in the form of our friends the ketone bodies, as well as citric, lactic, and pyruvic acids. At the end of the study period, they analyzed the fat content of the animals’ bodies and found significantly less fat on the carcasses of the high fat diet mice. Nevertheless, the AMA’s team of scholars didn’t even bother to review this study although it was published in the prestigious American journal Metabolism.5
There is more to the Kekwick and Pawan story. During the time they were proving the reality of the metabolic advantage of ultra low carbohydrate dieting, they detected and extracted a substance from the urine of the low carbohydrate dieters which, when injected into mice, caused the same metabolic events they had observed in the mice on low carbohydrate, indicating that fat was melting off the body. The carcass fat decreased dramatically, the ketone and free fatty acid levels rose, and, most significantly, the excretion of unused calories via urine and feces rose from a normal 10% to 36%! This substance was named fat mobilizing substance (FMS). FMS is the instrument of your metabolic edge; it enables you to sneak out some unused calories from your body that you wouldn’t be able to remove so easily on a low fat diet.
Kekwick and Pawan attributed hormonal properties to FMS, and at least four other research groups coming at the subject from a variety of directions felt they had identified fat mobilizers. Thus, the idea that you have a metabolic ally in sustaining weight loss has been demonstrated by a plentitude of researchers.6