How much dietary fat in therapeutic nutrition?

Abstract

Dietary fat has a less prominent role in realimentation than the alternate source of energy, carbohydrate. Presently available therapeutic diets, in typical feeding routines, provide only 3 to 120 g of fat per day. Three major factors contribute to fat underutilization: long-standing belief that fat is to blame for various vague symptoms of indigestion, misconception that daily fecal fat in excess of 7 g represents bowel dysfunction, and fear of fat-induced atherogenesis. None of these apply to refeeding starved and malnourished patients. The small intestine has a vastly underutilized capacity for fat absorption, and at the habitual fat intake of 100 g per day absorption is complete in the proximal one fifth of the gut. In patients requiring vigorous realimentation, the remaining small intestine should also be utilized. Dietary fat is well tolerated, and daily intakes of 500 g of polyunsaturated fat in a complete diet have not been associated with important side effects, while there was a significant improvement in body stores of fat and protein. Compared to diets high in carbohydrate, adequate intake of fat results in better nutrient utilization, less CO2 production and decreased lipogenesis and insulin requirements. Diets higher in fat are also better tolerated because of their lower volume and osmolality. The result is more effective absorption of calories and a faster nutritional recovery. Increased adipose tissue and protein reserve benefits patients who are in stress, immunocompromised, or debilitated. Adequate dietary fat should be considered for malnourished subjects with intact gastrointestinal function, and when intestinal absorptive capacity is reduced by surgery or disease.