According to the United States Department of Agriculture (USDA), caloric intake should be balanced with an individual's level of physical activity. A majority of Americans spend their time doing sedentary tasks, such as typing or watching TV. Fatty foods contain more calories; more physical activity is required to burn these calories.

Based on one study, patients with type I diabetes who adopted a low fat diet improved their sensitivity to insulin.

A long-term, in-depth study found that a low fat diet does not lower the risk for heart attacks, colon cancer, strokes, or breast cancer. The study suggested instead a more comprehensively healthy life-style, even if that life-style does include some healthy fats.

In sum, the overall evidence is mixed as to whether this diet may be beneficial for all patients. More evidence is needed before any firm recommendations can be made.

Even when people eat fewer high fat foods, they can still eat in an unhealthy manner by consuming foods that are high in starch, sugars, and protein, but devoid of more complete nutritional value. The USDA recommends that patients choosing a low fat diet also eat plenty of foods with documented nutritional value, such as vegetables, low fat dairy products, and whole-grains.

The American Medical Association recommends changing eating patterns, such as adopting substitutions, rather than meticulously counting calories or grams of fat. The exact number of calories is not as important as portion control and making everyday healthy selections of lower fat foods. They also suggest a gradual change in diet in order to prevent feelings of deprivation and withdrawal.

The medical profession's opinion of low fat diets is currently in flux. Patients are encouraged to discuss any diet with their doctor.