Background and aims: Hypoglycaemia is assumed to increase food intake, but there is little data on the magnitude or qualitative nature of this effect. We have therefore investigated the effects of insulin-induced hypoglycaemia on food intake at a test meal.
Methods: Sixteen healthy men (age 29.8 +/- 11 years; mean +/- SD) were studied; either insulin (0.05 units/kg) or saline was given intravenously in a double-blind crossover design. Blood glucose was monitored at regular intervals. Participants were given an ad libitum breakfast 20 min after injections and food intake and appetite scores were recorded.
Results: Blood glucose was unchanged following saline (4.3 +/- 0.4 to 4.4 +/- 0.3 mmol/L). There was a transient decline in blood glucose after insulin with a nadir at 20 min (4.31 +/- 0.34 to 2.41 +/- 0.45 mmol/L, p < 0.0001), which returned to baseline at 40 min. Total energy intake was 17% higher (1701.1 +/- 895.3 kcal vs 1427.7 +/- 815 kcal, p = 0.026) following insulin administration compared to that following saline. Macronutrient analysis revealed a significant increase in high-fat foods (muffins) (69.2 +/- 54.1 vs 29 +/- 42.3 g, p = 0.009) after insulin. Appetite scores were similar after saline and insulin despite these changes in food intake.
Conclusions: Transient insulin-induced hypoglycaemia increases energy intake. Participants consumed more fat after insulin compared to that after saline. High-fat foods can lead to passive overconsumption and have a low glycaemic index, which may prolong hypoglycaemia. Both factors could ultimately promote weight gain in individuals with recurrent hypoglycaemia.
Copyright 2004 John Wiley & Sons, Ltd.