People with Diabetes Do Better on Low-Carb Diets

For years, doctors and dietitians have been arguing about the best diet for people with diabetes. The American Diabetes Association has long recommended cutting fat, especially saturated fat, which leaves people eating more carbohydrates to meet their calorie needs. However, some studies suggest that low-carb diets can help prevent or control diabetes (American Journal of Clinical Nutrition, Oct. 2015).

Low-Carb Diets for People with Diabetes:

Danish researchers report that people with type 2 diabetes might do well to skip the Danish at breakfast. That’s because a diet lower in carbohydrates with more fat and protein can help people keep their blood sugar under control (Diabetologia, July 23, 2019). The investigators conducted a three-month long study. During that time, 28 people with type 2 diabetes followed low-carb diets higher in fat diet or higher-carb diets that adhered to dietary recommendations for diabetes.

Calories were controlled to prevent weight loss. (Weight loss is a benefit for many people with type 2 diabetes. Often dropping several pounds allows for better blood glucose control.)

People who followed the low-carb diet did better on regulating blood sugar. In addition, they had less fat in their livers at the end of the study. This is important, since non-alcoholic fatty liver disease complicates blood sugar control (Annals of Medicine, 2005).

Danish Researchers Weigh In Again on Low-Carb Diets in Diabetes:

When doctors diagnose type 2 diabetes, they often urge the patient to lose weight by following a low-calorie low-fat diet. Results of a clinical trial suggest that may not be the best way to improve their health. Restricting calories enough to achieve meaningful weight loss often results in hunger and is difficult to maintain.

To find out whether a diet without caloric restriction could be helpful, Danish researchers recruited 165 adults with type 2 diabetes (Annals of Internal Medicine, Dec. 13, 2022). They assigned two-thirds of the volunteers to follow a low-carb high-fat diet without any restriction on calories. The other third was asked to follow a high-carb low-fat regimen.

The dietary intervention lasted six months. Those following low-carb diets got no more than 26 percent of their calories from carbohydrates, while the high-carb group got 50 to 60 percent of their calories from carbohydrates and 20 to 30 percent from fats. Investigators measured HbA1c, serum lipids and markers such as blood pressure, waist circumference, weight and insulin resistance. They also assessed the participants for the presence of non-alcoholic fatty liver disease, a common complication.

Outcomes Favor Carb Reduction:

Although volunteers had been asked to keep their energy intake the same as before the study, both groups ate fewer calories. The low-carb diets provided about 13 percent of their calories from carbohydrates, while the high-carb group got 46 percent of their energy from carbs. Both groups improved their HbA1c while on the diets, with the low-carb group seeing a greater reduction. One downside: LDL cholesterol and apolipoprotein B was higher among the low-carb dieters after 3 and 6 months. On the other hand, people on low-carb diets lost more weight and more inches off their waists. They also had less insulin resistance. However, once people stopped the study diets and resumed their usual eating patterns, these improvements did not last.

The investigators concluded:

“In sum, we consider the beneficial effects of the LCHF [low-carb high-fat] diet to outweigh the minor increase in LDL cholesterol induced by the diet.”

Can Diet Reverse Type 2 Diabetes?

This research adds to the debate on reversing type 2 diabetes with lifestyle or diet. People can reverse this metabolic disorder with bariatric surgery, low-energy diets leading to weight loss, or low-carb diets (Nutrients, April 1, 2019). Other scientists have pointed out that the quality of carbs in the diet may be more important than the quantity. They cite studies showing that unrefined, high-fiber carbs can also contribute to reversal (Nutrients, July 2019).

The People’s Pharmacy Perspective:

People with type 2 diabetes or pre-diabetes should try low-carb diets to see if they help. We suspect that such a dietary program will help many but not all patients. On the other hand, avoiding highly processed foods, especially refined flour and added sugar, should benefit everyone.

Learn More:

We offer more information on blood sugar control in our Guide to Managing Diabetes. In addition, you may wish to listen to our interviews about exercise and botanical medicines to reverse diabetes. You’ll find them in Show 1036: How to Prevent Diabetes by Changing Your Life.

Our interview with Dr. Joel Fuhrman focuses on the dangers of processed food and what we could eat instead. It is Show 1122: Can You Keep Fast Food from Killing You?