Diet for type 2 diabetes: what diet comparisons have shown

Debates about diet for type 2 diabetes often focus on choosing the right diet. Recent large-scale trials suggest otherwise: results depended primarily on weight loss rather than the specific food composition used to achieve it. Below is an overview of what was measured and the resulting data. This is an analysis of research, not a prescription: a diabetes diet must be tailored by a physician.

What shifted the indicators in the trials

The most illustrative example is the British DiRECT study: 306 people with type 2 diabetes diagnosed no more than 6 years ago, across 49 primary care practices. After 12 months, remission—glycated hemoglobin below 6.5% without glucose-lowering drugs—was achieved by 46% of program participants compared to 4% in the standard care group.

But what matters more than the average figure is its dependence on weight change. Among those who gained weight, not a single person achieved remission; among those who lost 5–10 kg, it was 34%; among those who lost 10–15 kg, it was 57%; and among those who lost 15 kg or more, it was 86%.

This leads to the main conclusion: arguing about a specific diet makes sense only to the extent that it helps a person maintain changes.

What the DiRECT program looked like from the inside

It is often described as a "low-calorie diet," but in reality, it was a medical protocol. Participants stopped taking glucose-lowering and antihypertensive drugs, completely replaced their diet with a nutritional formula providing 825–853 kcal per day for 3–5 months, then gradually returned to regular food and received supportive follow-up.

Such a regimen cannot be repeated on your own: stopping medications and eating at such a calorie level is something that must be done under supervision and with monitoring of indicators. The fact that the program worked in a study does not turn it into a DIY guide.

Low-carb diets: strong effect for six months

A meta-analysis of 23 trials with 1,357 participants compared low-carb diets with control groups. After 6 months, 57% of participants achieved remission based on the HbA1c criterion of below 6.5%, compared to 31% in the control group.

There are caveats, without which this figure is misleading:

• If remission was defined strictly—without taking medication—the effect was smaller and lost statistical significance.
• By 12 months, there was little data, and the differences had almost disappeared.
• Very strict versions (less than 10% of calories from carbohydrates) performed worse than moderately low-carb ones.

This is a typical pattern for nutrition studies: the longer the observation, the smaller the difference between schemes. An analysis of the scheme itself is in the article about the keto diet.

What long-term lifestyle changes provide

The Look AHEAD study observed people with type 2 diabetes for about 9.6 years. An intensive lifestyle intervention program resulted in greater weight loss (8.6% vs. 0.7% in the first year and 6.0% vs. 3.5% by the end), better glycated hemoglobin, and better risk factor profiles.

However, the primary outcome—cardiovascular events—did not differ between the groups: a hazard ratio of 0.95 with a confidence interval of 0.83–1.09. The study was stopped early due to futility.

This result should be remembered as a counterweight to promises: improved lab results are not the same as a proven reduction in the number of heart attacks and strokes.

If you do not have diabetes yet

For people with elevated glucose but without diabetes, the most well-known answer was provided by the American Diabetes Prevention Program. Over an average of 2.8 years, the lifestyle intervention program reduced the incidence of diabetes by 58% compared to a placebo, and metformin by 31%; lifestyle proved more effective than the medication.

This is a case where the intervention was measured by a hard outcome—the onset of the disease—rather than by lab tests.

What this means for your plate

None of the listed studies identify "correct" or "forbidden" foods. The successful programs have something else in common:

1. Weight change that a person can maintain. This is what is linked to remission in DiRECT, not a specific set of dishes.
2. Support. In all programs, participants were guided: without this, trial results are harder to replicate.
3. Clear tracking. Knowing how much you have eaten is more important than choosing between "low-carb" and "Mediterranean"; how to start such tracking is described in the article on counting calories and macros.
4. Understanding what raises glucose for you specifically. General tables provide a guide, not an answer: see the materials on the glycemic index and glucose monitoring.

A separate topic is products labeled "for diabetic nutrition": what the regulations understand by this and why their calorie content is usually the same is analyzed in the article about diabetic products.

Where you need a doctor, not an article

A sharp reduction in carbohydrates while taking glucose-lowering drugs or insulin changes the dosage requirement. This is a direct risk of hypoglycemia, and changing your diet in such a situation must be done in consultation with your attending physician, not after reading a review of studies—including this one.

The same applies to any very low-calorie programs, stopping medications, and "entering remission": in all the cited works, this was done under supervision and with monitoring of indicators.

Count it from a photo

Frequently asked questions

Can type 2 diabetes remission be achieved through diet?

In the DiRECT study, 46% of program participants achieved remission after 12 months, compared to 4% in the control group, and it was strongly dependent on weight loss. The program included discontinuing medications and following a diet of 825–853 kcal under medical supervision — this is a medical protocol, not a DIY diet.

Is a low-carb diet better for type 2 diabetes?

Over a six-month period, a meta-analysis of 23 trials showed more remissions (57% vs 31%), but under a strict definition — without medication — the effect lost significance, and by 12 months, the differences almost disappeared.

Does lifestyle modification reduce the risk of heart attack in diabetes?

In the Look AHEAD study, over 9.6 years, an intensive program improved weight, HbA1c, and risk factors, but the incidence of cardiovascular events did not differ between groups (hazard ratio 0.95).

What should be done for prediabetes?

In the Diabetes Prevention Program, lifestyle modification reduced incidence by 58% over 2.8 years, and metformin by 31%. A doctor determines the specific strategy based on test results.

Is it necessary to eliminate sugar completely?

In the listed trials, the result is associated with overall changes in diet and weight, rather than the exclusion of a single product. The decision on specific restrictions is made by the attending physician, especially if glucose-lowering medications are prescribed.

Read next

• Diabetic products: what changes in them besides the price — The label "for diabetic nutrition" describes one property of a product — it contains fewer simple sugars than its standard counterpart.
• Glycemic index: what it measures and when it is useless to use — Glycemic index tables look like a list of allowed and forbidden foods: buckwheat has one number, potatoes have another, and it seems straightforward from there.
• Keto diet: what happens in the body and what comparisons have shown — The keto diet promises a non-standard mechanism: not counting calories, but switching metabolism to a different fuel.

This article is for general information. It is not medical advice, a diagnosis, or a prescription for treatment or a diet, and it does not replace a consultation with your doctor. If you have a health condition, are pregnant, take medication, or follow a diet prescribed to you, decisions about food belong with your doctor.

Figures from regulations, guidelines and studies are given as they stood when this article was prepared and may since have changed; check them against the primary sources. This article is not advertising, an offer, or individual advice, and neither the author nor the site owner is responsible for decisions taken on the basis of it.