Caloric Levels

Obviously the calorie level can and should be adjusted in accordance with response. There is no substitute for trial and error. It is also currently emphasized that 1,000 calories represent the smallest practical energy vehicle that can provide the recommended daily allowances of essential minerals and vitamins through usual food sources. For children, notably during puberty and adolescence, the minimum figure for a satisfactory diet on which to lose weight is close to 1,600 calories, with 1,800 often recommended to insure a margin of safety as well as to encourage adherence.

The protein component of the diet usually is calculated at one gram per two pounds of ideal body weight, of which at least two-thirds should be of animal origin, that is, of high nutritional value. Although this represents 12 to 20 per cent of the total calories, higher proportions still are advocated by some, more in the interest of lowered fat and carbohydrate content than of protein supply.

Fat should contribute 25 to 30 per cent of the total energy supply; however, 45 to 50 grams seem a minimum for practical purposes considering the appetite-satisfying and energy values of fats.

The carbohydrate remainder, some 40 to 60 per cent of the total calories, should also provide suitable bulk with sufficient fiber content (roughage) for normal bowel function and to sustain useful intestinal bacteria.

These figures represent tentative, average, and admittedly arbitrary proportions of the principal food sources. Enthusiasm for more extreme prescriptions—for example high fat or high carbohydrate diets—are revived periodically by experimental and clinical observations, and occasionally by those more interested in making a fast dollar than reducing fat. These programs commonly are without adequate scientific foundation. They apply to only a relatively small proportion of obese people, and are inconsistent with good long-term dietary practices.

Salt intake, although ordinarily in excess of needs, should not be restricted in reducing diets except when directed by the physician. In all likelihood, prohibiting the use of salt has contributed to weight reduction as much by decreasing the appeal of food as well as by causing water loss.

Fluids should be consumed as desired, preferably in sufficient quantities to permit a daily urine output of at least one quart. They combat the tendency to constipation that sometimes troubles patients in the initial stages of a reducing program. There is at present insufficient information to recommend routine limitation of fluid intake as a means of caloric control.

Liquid formula diets unquestionably have helped many persons to lose weight. Although some of these preparations combine the merits. of economy, acceptability, and nutritional balance, these too lend themselves chiefly to short-term intensive weight loss, postponing the day of reckoning when practical considerations inevitably oblige the patient to return to more usual and probably more complete foodstuffs. Without developing proper eating habits, the prospects for effective maintenance of desired weight seem poor.