Less food, less hunger: reports of appetite and symptoms in a controlled study of a protein-sparing modified fast

This study compared reports of appetite and symptoms in 28 obese subjects randomly assigned to either a 500 calorie protein-sparing modified fast (PSMF) or a 1200-kcal balanced diet. During the first comparison month, subjects consuming the PSMF lost significantly more weight and reported significantly less hunger than did subjects consuming the 1200 kcal diet. Similar results were obtained for the second month, but differences in hunger were not statistically significant. There were no significant differences between conditions in subjects' ratings of their preoccupation with eating or in their ratings of the acceptability or disruptiveness of their diets. PSMF subjects reported significantly greater problems with cold intolerance, constipation, dizziness, dry skin, and fatigue. These symptoms remitted completely, however, when PSMF subjects consumed a 1200-kcal balanced diet. There were no significant differences between conditions in subjects' reports of psychological functioning. Results are discussed in terms of the need for further research to identify the characteristics of PSMF which confer anorexia.