Pennington Abstracts 1

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The use of fat in a weight reducing diet.
            (Pennington, 1951)  Download
It can easily be seen that great amounts of carbohydrate in the diet increase the fat storage mechanism. While the overconsumption or carbohydrates appears to be the cause of obesity, it is not a simple matter. It depends on the ability to break down pyruvic acid. The cause of obesity becomes an inability to oxidize sugar and starch. The safest and most effective method of weight reduction is to completely eliminate carbohydrate from the diet and allow an ad libitum intake of protein and fat. The physiologic situation which promotes fat mobilization is brought into play with great effectiveness.

A reorientation on obesity.
            (Pennington, 1953a) Download
During the past half century, investigation of the problem of obesity has followed two distinct lines: that of intermediary metabolism and that of energy exchange.

Obesity: overnutrition or disease of metabolism
            (Pennington, 1953b) Download
Although it is widely believed that physiological experiments have proven the absence of any metabolic defect in the etiology of obesity, a clear-cut analysis of the manner in which they are presumed to have done so is difficult to find. Discussions of the subject often emphasize that the energy intake must exceed the expenditure when obesity is developing; but this elementary knowledge, deducible from the law of conservation of energy, needs no experiment. A treatment of obesity, alternate to that of caloric restriction, takes into account the metabolic defect in obesity, aims at a primary decrease in the excessive energy stores, and allows for weight reduction without any decline in the energy expenditure and without any enforcement of caloric restriction.


 

Pathophysiology of obesity.
            (Pennington, 1954b) Download
The widely prevailing opinion that energy exchange studies have proved the absence of any metabolic defect in obesity has, for many years, relegated biochemical details of this condition to a position of minor importance. Analysis of energy exchange experiments on the basis of their evidence for or against a passive dependence of the adipose deposits on the caloric balance, however, indicates that many cases of obesity must be attributed to a metabolic defect in- volving the storage of body fat (1). Details of fat metabolism, therefore, can no longer be considered inconsequential. Instead, it appears that they form the necessary basis for an understanding of the pathogenesis of obesity and its rational treatment

Treatment of obesity: developments of the past 150 years.
            (Pennington, 1954a) Download
The concept that common obesity arises from some cause other than simple overfeeding has, in the past, suffered from lack of an effective treatment to fit a proposed rationale and also, in at least one instance, from lack of a rationale to fit an effective treatment. The history of obesity since the end of the 18th century is reviewed, with particular attention to events connected with the Banting dietary. This treatment appears to have been, originally, one in which carbohydrates were restricted but the total food intake was not restricted. Lacking a rationale, it became modified to fit current concepts; it underwent transformation into a low calorie diet in which fat was greatly restricted. Another, more recent, diet in which carbohydrate is restricted while the total caloric intake is not restricted is presented. The rationale for this treatment is indicated.

Pyruvic acid metabolism in obesity.
            (Pennington, 1955) Download
Many years ago Zuntz reported the case of a man who gained weight on a high carbohydrate diet and lost weight on a high fat diet of equal caloric value. The greater efficiency of high fat diets in weight reduction has often been puzzling in view of the wide- spread acceptance of Rubner's "isodynamic law." This law, which stands dimly at the basis of current nutritional theory, holds that, calorie for calorie, carbohydrate and fat are interchangeable in respect to their effects on the energy balance. Controlled experiments on the relative efficiency of carbohydrate, fat and protein in weight reduction diets indicate that obese people lose more weight when most of the calories are derived from fat. These findings are explained by a concept of obesity as due to an impairment in the oxidative pathway of pyruvic acid. Recent advances in the biochemistry of pyruvic acid are reviewed and an attempt is made to identify the precise point at which the metabolic defect occurs.

 

Weight Reduction
            (Pennington, 1958) Download
To the Editor:—  Dr. Max Wishnofsky (J. A. M. A.166:964-965 [Feb. 22] 1958) is in error in stating "The thesis of Pennington is that when an obese individual is on a high-fat, high-protein ad libitum diet, a substantial loss of weight will occur even when there is no negative caloric balance." Such a statement appears nowhere in any of the papers I have written, nor is it implied in them. On the contrary, my statements on the matter have been very clear. For example: "In the treatment of obesity, the aim of which is to reduce the size of the adipose deposits, it is axiomatic that the caloric expenditure must exceed the intake" (J. Clin. Nutrition1:100-106 [Jan.] 1953). Again: "The overall determinant in weight reduction is the degree to which the caloric expenditure exceeds the intake" (New England J. Med.248:959-964 [June 4] 1953). My thesis on weight reduction concerns itself with the manner in which a negative caloric balance is to be brought about. According to my plan, "treatment would be directed primarily toward mobilization of the adipose deposits, and the appetite would be allowed to regulate the intake of food needed to supplement the mobilized fat in fulfilling the energy needs of the body" (/. Clin. Nutrition 1:100-106 [Jan.] 1953).

Calorie intake in relation to body-weight changes in the obese.
            (Kekwick and Pawan, 1956) Download
Overweight subjects were put in three groups. Each group received 1000 calories per day. One group was fed 90% carbohydrates, the second group 90% protein, and the third group 90% fat. The group receiving 90% carbohydrates gained an average of 0,24 pounds per day of the study. The group receiving 90 protein lost an average of 0,6 pounds per day of the study, and the group receiving 90% fat lost an average of 0,9 pounds per day of the study. This clearly demonstrates the superiority of diets high in protein and fats over diets high in carbohydrates. Note that each group received only 1000 calories per day. It's interesting to note that even at the very restricted level of 1000 calories per day, subjects fed 90% carbohydrates actually GAINED weight.


 

Fat Emulsions for Intravenous Use
            (Stare, 1950) Download
Emulsions made of highly refined vegetable oil, such as we and others have used clinically, do not contain cholesterol. These are not emulsions of cholesterol but of vegetable oils free of cholesterol. As such they are good solvents of choles¬ terol. On the assumption that they may be "solvents in vivo" for cholesterol, we are using them in an attempt to dissolve the cholesterol from atheromatous plaques produced in rabbits by feeding them cholesterol. Hence, properly prepared fat emulsions may actually become of value in the treatment of atherosclerosis.

Treating overweight patients.
            (Thorpe, 1957) Download
The simplest to prepare and most easily obtainable high-protein, high-fat, low-carbohydrate diet, and the one that will produce the most rapid loss of weight without hunger, weakness, lethargy, or constipation, is made up of meat, fat, and water. The total quantity eaten need not be noted, but the ratio of three parts of lean to one part of fat must be maintained. Usually within two or three days, the patient is found to be taking about 170 Gm. of lean meat and 57 Gm. of fat three times a day. Black coffee, clear tea, and water are unrestricted, and the salt intake is not reduced. When the patient complains of monotony, certain fruits and vegetables are added for variety. The overweight patient must be dealt with as an individual. He usually needs help in recognizing the factors at work in his particular case as well as considerable education in the matter of foods.

 


References

Kekwick, A and GL Pawan (1956), ‘Calorie intake in relation to body-weight changes in the obese.’, Lancet, 271 (6935), 155-61. PubMed: 13347103
Pennington, AW (1951), ‘The use of fat in a weight reducing diet.’, Del Med J, 23 (4), 79-86. PubMed: 14822575
——— (1953a), ‘A reorientation on obesity.’, N Engl J Med, 248 (23), 959-64. PubMed: 13046654
——— (1953b), ‘Obesity: overnutrition or disease of metabolism’, Am J Dig Dis, 20 (9), 268-74. PubMed: 13080244
——— (1954a), ‘Treatment of obesity: developments of the past 150 years.’, Am J Dig Dis, 21 (3), 65-69. PubMed: 13138551
——— (1954b), ‘Pathophysiology of obesity.’, Am J Dig Dis, 21 (3), 69-73. PubMed: 13138552
——— (1955), ‘Pyruvic acid metabolism in obesity.’, Am J Dig Dis, 22 (2), 33-37. PubMed: 13228386
——— (1958), ‘Weight Reduction’, JAMA, 166 (17), 2214-15. PubMed:
Stare, FJ (1950), ‘Fat Emulsions for Intravenous Use’, JAMA, 142 (10), 748-748. PubMed:
Thorpe, GL (1957), ‘Treating overweight patients.’, J Am Med Assoc, 165 (11), 1361-65. PubMed: 13475044