An appreciation of the physiology of fasting is essential to the understanding of therapeutic dietary interventions and the effect of food deprivation in various diseases. The practice of prolonged fasting for political or religious purposes is increasing, and a physician is likely to encounter such circumstances. Early in fasting weight loss is rapid, averaging 0.9 kg per day during the first… Read More

During a total fast in obese subjects, the daily rate of nitrogen excretion undergoes only a small further decline after 2 wk, the excretion rate being about 5 g N/day. At this time, ammonium and urea each constitute about one-half of this excretion. The purpose of this study was to consider two alternative hypotheses: first, that the near plateau in nitrogen excretion represents an… Read More

We have studied (125I)-insulin binding and insulin dose response relationships of (14C)-methylglucose transport conversion of (14C)-glucose to CO2 and total lipids, and lipolysis at 37 degrees C and pH 7.4 in adipocytes from obese patients before (n = 15) and after fasting for 10 days (n = 6). Studies of adipocytes from obese before fasting showed a significant reduction of… Read More

The urinary excretion of acetylcarnitine was studied in patients with diabetic ketosis before and during insulin therapy and in normal-weight and obese subjects during fasting. In the diabetic ketotic patients, acetylcarnitine represented 61% of the total acylcarnitine excretion. During the first 24 h of insulin treatment, acetylcarnitine excretion decreased and on the 5th day of treatment was… Read More

The effect of complete fasting on the serum concentrations of the iodothyronines 3,5-diiodothyronine (3,5-T2), 3,3'T2, 3', 5'-T2 and 3'-monoiodothyronine (3'-T1) was evaluated. Fourteen obese women underwent a complete fasting for 4 days. Caloric restriction resulted in the following serum hormone levels (before vs 3. day): T4: 103 vs 109 nmol/l (NS), T3: 1.83 vs 1.24… Read More

Arterial (A) and renal venous (RV) concentrations and net splanchnic exchange of glucose, fructose, lactate, pyruvate, glycerol, and alanine were studied in the basal state and during a 135-min intravenous infusion of fructose at 2 mmol/min in healthy subjects after a 60-h fast. After 45 min of the fructose infusion, somatostatin (9 microgram/min) was infused for 60 min to induce… Read More

To determine whether the differences in fasting glucose responses in men, women and children could be related to differences in glucoregulatory hormone secretion or availability of circulating gluconeogenic substrates, 20 adults (10 men and 10 women) were fasted for 86 hr and 15 children (6.1 +/- 0.8 yr, mean +/- SE) were fasted for 30 hr. Circulating concentrations of glucose, ketone bodies,… Read More

To determine whether acid-base balance regulates hydrogen ion production, seven obese volunteers were given NaHCO3 and NH4Cl (2 mmol.kg-1.day-1) during two separate 7-day fasts. On days 5-7 plasma bicarbonate was lower in the NH4Cl fasts (14.0 +/- 1.4 mM) than in the NaHCO3 fasts (18.3 +/- 1.1 mM), while urine pH and net acid excretion did not differ. Acid… Read More

The effects of vegetarian fasting were evaluated in 14 grossly obese patients who participated in a program comprising 5 weeks' fasting in a lactovegetarian health center. Before and after the fasting period the patients were hospitalized and put on a standardized weight-maintaining diet; at the health center they consumed vegetable juices containing less than 1 MJ and 3… Read More