Research

Energy balance

Intermittent very-low-calorie diet (VLCD) therapy (400-600 kcal/day for 1-5 days per week) combined with moderate caloric restriction produces significantly greater weight loss and improves glycemic control (specifically HbA1c normalization) in type 2 diabetes compared to moderate caloric restriction alone.

For individuals with Type 2 Diabetes who are overweight, incorporating short periods of very low-calorie intake (400-600 calories) into a weekly routine, alongside moderate calorie intake on other days, can lead to significantly greater weight loss and better blood sugar control than maintaining a moderate calorie diet alone. This approach requires strict adherence to the VLCD days, potentially supported by provided meals, and should be done under medical supervision.

GoodSupportsHIGH confidence
The principal finding is that periodic VLCD produced nearly twice as much weight loss as SBT alone. In addition, an initial period of 5 days of VLCD therapy resulted in more rapid improvements in FPG than did SBT... more subjects in the 5-day group attained a normal HbA1c value at the end of 20 weeks when compared with those receiving SBT.
Katherine V. Williams et al. · Diabetes Care · 1998

Why this rating

Randomized controlled trial with n=54, clear outcomes, but short duration (20 weeks) and specific population (obese T2D).

Source

The Effect of Short Periods of Caloric Restriction on Weight Loss and Glycemic Control in Type 2 Diabetes

Katherine V. Williams et al. · Diabetes Care · 1998

DOI 10.2337/diacare.21.1.2

rct · n=54Cited 195×
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DOI resolved against Crossref · corpus check 2026-06-10

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