Weight reduction. Renal mineral and hormonal excretion during semistarvation in obese patients

Three patients with exogenous obesity were studied while fed a 400-kcal constant metabolic diet, provided as a single daily meal served at consecutive ten-day periods, starting with either the "breakfast" protocol at 8 AM or the "dinner" protocol at 5 PM. Both patients 1 and 2 had notably greater weight loss with the breakfast protocol than with the dinner. However, in patient 3 this difference was not demonstrated. Urine samples, collected at four-hour intervals throughout the studies and analyzed for sodium, potassium, calcium, phosphorus, 17-hydroxycorticosteroids, and aldosterone secretions, showed differences in excretion of minerals and hormones with the timing of meals. The data tentatively show an achievement of greater weight loss when the isocaloric diet is given at 8 AM.