Mediterranean Diet Combined With Exercise Reduces Diabetes Risk

• A Mediterranean diet, combined with calorie reduction and exercise, reduced the risk of type 2 diabetes by 31%.
• In a study of older adults, those who followed this lifestyle lost an average of 3.3 kilograms (just over 7 pounds) of body weight.
• Experts say that even small changes towards a healthier diet and more exercise can be beneficial in reducing type 2 diabetes risk

Eating a calorie reduced Mediterranean diet together with lifestyle changes can reduce the risk of developing type 2 diabetes by 31%.

Researchers in Spain found that following this eating pattern, participating in moderate exercise, and having professional weight loss guidance could be highly effective prevention tools against diabetes. The findings were published on August 26 in Annals of Internal Medicine.

“Diabetes is the first solid clinical outcome for which we have shown — using the strongest available evidence — that the Mediterranean diet with calorie reduction, physical activity and weight loss is a highly effective preventive tool,” Miguel Ángel Martínez-González, professor of Preventive Medicine and Public Health at the University of Navarra, adjunct professor of Nutrition at Harvard University, and one of the principal investigators of the project said in a press statement.

“Applied at scale in at-risk populations, these modest and sustained lifestyle changes could prevent thousands of new diagnoses every year. We hope soon to show similar evidence for other major public health challenges,” Martínez-González continued.

To determine whether a Mediterranean diet with reduced calories could be beneficial in preventing type 2 diabetes, the researchers split the participants into two groups.

The first group had a moderate exercise plan and professional guidance, and ate a calorie-reduced Mediterranean diet with about 600 calories less than the second group, who just ate a regular Mediterranean diet with no exercise plan or calorie reduction.

As well as reducing the risk of type two diabetes, the researched found that those in the first group who ate a calorie reduced Mediterranean diet and exercised lost an average of 3.3 kilograms or 7.3 pounds of body weight. They also had a reduction of 3.6 centimeters (1.4 inches) in their waist circumference.

In comparison, the second group lost 0.6 kg (1.3 pounds) and just 0.3 cm (0.1 inches) of waist circumference.

This suggests the calorie reduced Mediterranean diet together with exercise prevented roughly three out of every 100 participants in the study from developing type 2 diabetes.

“31% is a substantial and meaningful reduction” said Marilyn Tan, MD, an endocrinologist and clinical associate professor of medicine at Stanford.

“It’s not surprising, per se, but I would call it encouraging. We’ve known for a long time that a cleaner, less processed diet, reduced calories, and more exercise contribute to better metabolic health. In addition, professional support for weight loss is helpful not only for education but also for keeping people on track,” Tan told Healthline.

More than 38 million Americans live with diabetes, and of these, 90-95% live with type 2 diabetes. Rates of young people developing diabetes are also rising.

“In the U.S., prevalence and incidence of diabetes are tied to body weight and obesity (higher than global average), dietary quality (which is lower than the global average), and physical activity (which is also very low with people in sedentary jobs and doing a lot of commuting to and from work),” Dana Hunnes, PhD, senior dietitian supervisor at the RR-UCLA Medical Center told Healthline.

“Also, our healthcare system is not equal for all. Many people cannot afford healthy food, good health care, and depend on ‘what seems like inexpensive’ foods that cause a lot of health problems in life. So, this is sadly very concerning, and there are [multiple] factors that are responsible for these trends,” Hunnes noted.

Lifestyle changes can prevent or delay type 2 diabetes, and experts say both exercise and the Mediterranean diet are useful change people can implement.

“The Mediterranean diet emphasizes whole grains, vegetables, fruits, legumes and nuts; overall this is reducing carbohydrate and sugar intake which in turn reduces insulin secretion and increases fat breakdown, both improving diabetes risk,” said Mir Ali, MD, board certified general surgeon, bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, California.

“I suggest to my patients to start with small changes, like eliminating sugary drinks, and build on improving the diet from there. Also, with exercise, it is more important to be consistent (30 minutes/day, 5 days a week) than having irregular intense exercise, and even walking is beneficial. If it’s not possible to get in the exercise in one session, breaking it up throughout the day is acceptable. Again, starting with small changes and building on that,” Ali said.

Whilst the Mediterranean diet and lifestyle interventions in the study show significant benefit, Tan notes that there may still be barriers for some.

“For many people, it may be difficult to implement. In general, healthier whole foods, olive oil, healthy nuts, fruit, etc., are more expensive than processed foods,” Tan said.

“It also takes time to buy and prepare these foods, and many people don’t have time for the meal preparation. Physical support for weight loss is not always available locally or covered by insurance. In addition, most people are aware that physical activity is important, but this also relies on having time and a safe place to exercise,” she continued.

In the study, the reduced-calorie group ate 600 fewer calories than their peers. The experts note that while tracking and reducing calories can seem overwhelming, some strategies can make it more manageable.

“One way to start is by reducing portion size,” Ali said. “Some people will get smaller plates or use other guides to help reduce portions. Others will use apps or other methods to help reduce calories. Again, it is easier to make small changes that are sustainable and build on those changes. Unfortunately, no one method works for every person.”

There are some risk factors for type two diabetes that can’t be changed, like age or having a family history of diabetes. But experts say weight loss can still make a notable difference to reducing risk.

“Weight loss in someone who is overweight or obese can help reduce diabetes risk significantly,” Tan said. “It’s been established that a 5–10% weight reduction in someone who is overweight or obese can reduce type 2 diabetes risk.”