Effects of Low-Carb Diet on Appetite, Glucose, and InsulinResistance

An Atkins-like low-carbohydrate diet can help improve glucose control,insulin sensitivity, and glycated hemoglobin (A1C), according to a trialreported in the March 15, 2005, issue of Annals of InternalMedicine.

Researchers studied diet in a controlled clinical environment among 10obese people with type 2 diabetes. While staying in an inpatient hospitalunit, participants were instructed to continue their usual diet, consisting ofmeals from the hospital kitchen augmented by food from the outside, for thefirst 7 days of the trial. Participants were encouraged to eat as much as theywanted of name-brand foods—McDonald's sandwiches, Dunkin' Donuts bakeryproducts, Oreo cookies—for which dietary information was readilyavailable.

After 7 days, all participants switched to a low-carb diet that reducedcarbohydrates to about 21 g/day but permitted as much protein and fat as theydesired. People were allowed to choose from a menu of foods prepared in thehospital kitchen. They remained on the low-carb diet for the next 2 weeks. Allparticipants were encouraged to maintain their usual level of physicalactivity.

While on the low-carb diet, the average energy intake decreased from 3,111kcal/day to 2,164 kcal/day, which contributed to an average weight loss of 3.6lb during the 14-day low-carb diet phase. The average 24-hour blood glucoselevels became normalized, the average A1C level dropped from 7.3% to 6.8%, andinsulin sensitivity improved by about 75%, according to researchers.

Although the study had a small number of participants and lasted only a fewweeks, it was strictly controlled and provides evidence concerning the valueof low-carb diets that may merit further exploration in larger controlledstudies.