Diabetes/Glucose Intolerance

Good evidence suggests that low energy (~850 kcal/day) total diet replacement for three months with weight loss of approximately 15 kg followed by structured food reintroduction can induce remission of type 2 diabetes (T2DM) at 12 months in about 50% of adults with a BMI of ≥27 kg/m² who have had T2DM for less than six years. Remission rates appear to decrease at 24 months.

Fair evidence suggests that formula meal replacement diets (one to two meals per day) with weight loss of approximately 9 kg can induce T2DM remission at 12 months in about 10% of adults with a BMI ≥25 kg/m² who have had diabetes for approximately five years. Remission rates appear to decrease each year in the four years following the intervention.

Limited evidence suggests that a Mediterranean diet, very low carbohydrate ketogenic diets and food-based very low energy diets may also induce T2DM remission in adults, but there is not enough evidence to make a recommendation.

A 2022 systematic review found that diets with an initial low energy total diet replacement (800 to 850 kcal/day) for three months with a weight loss of 12 kg followed by structured food reintroduction and support for weight loss maintenance induced T2DM remission in 46 to 61% of adults (T2DM duration <6 years) after one year compared to 4 to 12% in those following a usual diet.
Grade of Evidence A

Liquid meal replacement diets with a weight loss of approximately 9 kg induced T2DM remission in 11% of individuals (median T2DM duration five years) after one year compared to 2% in the standard care control group.
Grade of Evidence B

A Mediterranean diet induced T2DM remission in 15% of individuals compared to 4% in the low fat diet control group.
Grade of Evidence C

Very low carbohydrate ketogenic diets and food-based very low energy diets may also induce remission of T2DM in adults, although the former carries a risk for metabolic ketoacidosis, especially for individuals who take SGLT2 inhibitor medications.
Grade of Evidence C

In RCTs involving total diet replacement and liquid meal replacement that lasted longer than 12 months, the rates of diabetes remission appear to decrease up to four years in both the intervention and control groups, although every 1 kg reduction in body weight was associated with a 7% higher chance of remission at five years.
Grade of Evidence B

Findings may not be applicable to non-European individuals and, given that few studies lasted longer than 12 months, the ability of dietary approaches to maintain T2DM remission long term is unknown. Adverse events were not discussed.
Grade of Evidence C

The 2022 clinical practice guidelines from Diabetes Canada, based on the same evidence summarized in the systematic review described above, recommend low calorie diets (800 to 850 kcal/day) with meal replacement products for three to five months with a weight loss goal of >15 kg, followed by structured food reintroduction and increased physical activity to maintain weight loss to induce remission in nonpregnant adults who have had T2DM for less than six years, do not use insulin, have an A1C <12% and whose BMI is between 27 and 45 kg/m².
Grade of Evidence A

The guidelines also recommend a calorie-restricted diet with a weight loss goal of 5 to 7% of initial body weight to induce remission in nonpregnant adults who have had T2DM for less than 10 years, do not use insulin, have an A1C of <9% and whose BMI is >25 kg/m².
Grade of Evidence C

Remission should only be considered for individuals who are interested in remission, who do not have eating or mental health disorders and who do not require antihyperglycemic medications for their renal or cardiovascular benefits.
Grade of Evidence C
 

The 2021 position statements from Diabetes Australia and Diabetes UK, based on the same evidence summarized in the systematic review described above, state that very low energy diets (800 kcal/day or less) with a weight loss goal of at least 15 kg or 10 to 15% of initial body weight can induce remission in adults with overweight or obesity (BMI not specified) within the first few years of T2DM .
Grade of Evidence A

The position statements also recognize that other diets (e.g. low carbohydrate, low fat or Mediterranean diets) may also induce T2DM remission, although with less success.
Grade of Evidence C

T2DM remission is generally defined as A1C<6.5% without the use of antihyperglycemic medications for at least three consecutive months. Weight loss appears to be the main driver of T2DM remission, as it seems to restore beta cell function in the pancreas and reduce insulin resistance in the liver. The impacts of remission on the long-term macro- and microvascular risks associated with T2DM are unknown.

T2DM remission is not possible for all individuals due to structural barriers, including colonialism, racism and food insecurity. Additionally, attempting T2DM remission requires a substantial amount of clinical and psychosocial support. Weight loss through lifestyle interventions alone is not possible or feasible for many individuals because of personal, environmental and systemic reasons.