By Corrie Pelc on October 16, 2023 — Fact checked by Kelsey Costa, MS, RDN
Type 2 diabetes has become one of the most widespread health conditions worldwide. While medications can help people manage their symptoms, some medical experts suggest that lifestyle changes, such as following a low-calorie diet, can reverse this chronic condition. But are such changes always sustainable?
Is it always safe to follow a low-calorie diet to send type 2 diabetes into remission? We investigate. Image credit: Anna Tabakova/Stocksy.
Around 96% of the estimated 537 million people around the world who have diabetes are living with type 2 diabetes. The number of people with diabetes is expected to rise to about 783 million by 2045.
While there is currently no cure for type 2 diabetes, its symptoms can be managed — and even reversed — through weight loss and lifestyle changes, such as exercising more and following a healthy diet.
Recently, some scientists have focused on the use of a low-calorie diet as the answer to type 2 diabetes remission. However, some say following a low-calorie diet for the long term may not be feasible in the real world.
What exactly is a low-calorie diet? How could it help reverse type 2 diabetes? And is this type of diet appropriate for everyone with type 2 diabetes?
Medical News Today spoke with five medical experts on this subject to find out whether or not a low-calorie diet is the right move for people with type 2 diabetes.
Type 2 diabetes is a condition where the body can no longer use or produce insulin correctly. One of the main causes of type 2 diabetes is having overweight or obesity.
“Type 2 diabetes is a weight-related disorder in which people are not able to make enough insulin for their [bodies],” Dr. Jennifer Cheng, chief of endocrinology at Hackensack Meridian Jersey Shore University Medical Center explained to MNT. “They develop insulin resistance when gaining weight. The insulin goes into the fat tissue instead of their bloodstream. The improvement of glycemic control is related to weight loss.”
Because of type 2 diabetes’ ties to weight, most treatment options revolve around healthy lifestyle changes, including dietary changes.
In general, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) recommends that people with type 2 diabetes follow a diet focusing on vegetables, fruit, protein, whole grains, dairy, and heart-healthy fats.
Additionally, past research suggests that specific diets — such as the DASH diet, Mediterranean diet, and paleo diet — could also have a positive impact on type 2 diabetes
A person on a low-calorie diet will consume between 1,000 and 1,500 calories a day, depending on their specific needs.
The purpose of a low-calorie diet is to create a calorie deficit that can ultimately lead to weight loss. A consistent 500 to 1,000 calorie deficit can help a person lose 1 to 2 pounds (0.4–0.9 kilograms) per week.
The Dietary Guidelines for Americans suggest a healthy diet consists of:
- focusing on fruits and vegetables for half of each meal
- choosing whole grains and protein
- selecting low-fat or fat-free dairy, lactose-free dairy, or fortified soy versions
- limiting sodium, saturated fat, and sugar.
Because the amount of calories needed varies between each person, they should talk to their doctor or registered dietitian before starting a low-calorie diet.
Dr. Kathleen Axen, department chairperson and deputy chair graduate nutrition for Health and Nutrition Sciences at Brooklyn College, is the co-author of a study on low-calorie diets and type 2 diabetes published in June 2021.
According to her, because insulin resistance is a major feature of type 2 diabetes and weight loss reduces insulin resistance, that would be a way for a low-calorie diet to have put diabetes in remission.
“Decreases in adipose tissue mass lower blood levels of free fatty acids, which would mitigate their effects on liver metabolism, allowing liver pathways to be more responsive to insulin,” she added. “Lower insulin resistance results in better control of blood glucose and blood lipids.”
Monique Richard, a registered dietitian nutritionist, owner of Nutrition-In-Sight, and national media spokesperson for the Academy of Nutrition Dietetics, said if a person is decreasing their caloric intake, they are also decreasing the amount of carbohydrates they consume, which affects blood glucose levels.
“Lower blood glucose spikes will in turn decrease insulin needs from the pancreas preserving the function of the beta cells that make insulin. The process of the body storing additional energy (calories) as fat will likely be greatly diminished. Depending on the calorie deficit, pathways to burn the excess glucose and fat stores will also become active in order to meet the body’s needs.”
– Monique Richard
“The entire cascade of metabolic functions within the body will be affected, likely allowing cells to become more sensitive to the glucose-insulin process since it is not overwhelmed by excess,” Richard added.
Previous studies have provided evidence that following a low-calorie diet can help place type 2 diabetes into remission for the long term.
The American Diabetes Association defines diabetes remission as sustaining normal blood sugar levels — an HbA1c level of less than 6.5% — for 3 months or longer.
A study published in June 2021 found people who followed an intermittent very-low calorie diet were able to achieve optimal glycemic control.
And other research published in September 2022 reported one-third of its study participants were able to place their diabetes into remission for at least 8 years after following a very low-calorie diet.
At the Annual Meeting of the European Association for the Study of Diabetes 2023, Dr. Roy Taylor, professor of medicine and metabolism at Newcastle University in Newcastle, United Kingdom, spoke in support of a low-calorie diet leading to lasting remission of type 2 diabetes in a real-world setting.
He told MNT that the proof for this can be found in a series of five major studies conducted in Newcastle that confirm the Twin Cycle Hypothesis.
“The latter used our study data from studies on people with and without type 2 diabetes and predicted in 2008 that a period of low-calorie diet would sharply decrease the fat content of the liver,” Dr. Taylor explained.
“That would bring benefits in two ways. It would improve the response to insulin and allow the body to return to normal the output of glucose from the liver. Crucially, it would return to normal the raised output of fat from the liver which was soaking all tissues of the body in excess fat, but the insulin-producing cells in particular would be suppressed by this.”
– Dr. Roy Taylor
“So the Twin Cycle Hypothesis predicted a waking up of the insulin-producing cells once this metabolic stress was removed,” he continued.
“To my surprise, the critical study published in 2011 showed this is exactly what happens providing the low-calorie diet is sufficient to decrease body weight [by] 10–15kg. Our subsequent studies sorted out details, and especially showed that remission lasted as long as the weight regain was avoided,” said Dr. Taylor.
While evidence seems to support a low-calorie diet as an option for placing diabetes into remission, it is important to note that this type of dietary intervention may not be for everyone.
“There are people with diabetes who are not overweight to start with, as it is not a uniform disease,” Dr. Axen said. “They should not lose more weight, as they will lose lean body mass. Those with high blood glucose levels or who have other complications can’t rely only on diet. They risk exacerbation of retinopathy, nephropathy, neuropathy, and cardiovascular disease.”
“A low-calorie diet is not appropriate for everyone,” Dr. Cheng also cautioned. “It can be dangerous for those who are on this type of diet and have a high risk for low sugars, without enough calories, especially in older adults. If they are not obese, then there is not as much benefit for a low-calorie diet.”
Starting a low-calorie diet is one thing — staying on it for the long-term is another.
“Our culture makes it difficult to avoid some of the more nuanced changes that may be associated with a low-calorie diet,” Richard explained.
“For example, many restaurant meals and convenience foods offered tend to have more calories than making the meal yourself. If the person is not invested in learning about healthier recipes or products to make meals, it may not be ‘real-life’ or practical for them. Eating is also a very important social connection to restrict for a long duration and could affect mental and physical health,” she added.
Dr. Pouya Shafipour, a board-certified family and obesity medicine physician, of Providence Saint John’s Health Center in Santa Monica, CA, told MNT that the trick to a sustainable low-calorie diet is in the types of calories reduced.
“When we talk about [a] low-calorie diet, it depends on what type of calorie you’re reducing because everyone’s body has fat reserves that if we can eat, in a sense, […] then we don’t necessarily need a lot of calories,” he detailed.
“So if the low-calorie diet takes into consideration the correct macronutrients, if you’re cutting calories mostly from carbohydrates, but not necessarily from protein and fat, then it forces the body to start utilizing the stored fat reserves when it runs out of glucose. And then it becomes more sustainable because hunger won’t be an issue,” Dr. Shafipour explained.
“If you’re just cutting calories but still kind of eating preservatives, starch, and sugar, then it doesn’t become sustainable because you’re constantly hungry,” he further explained.
When it comes to dietary changes for people with type 2 diabetes, Richard said that in general, it is helpful for many people to decrease the amount of excess sugar in their diet from processed foods, which naturally decreases calories and makes room for more nutrient-dense choices like fruits and vegetables.
“Registered dietitian nutritionists (RDNs) are specifically trained in medical nutrition therapy (MNT) which offers specific nutrition interventions for specific disease states,” she continued. “For those with type 2 diabetes, meeting with an RDN would be beneficial to understand what nutrition and lifestyle modifications may be most appropriate, applicable and practical for the individual to implement.”
Dr. Shafipour said that a lower carbohydrate diet, such as the Mediterranean diet, can be sustainable.
“If the diet is something that at least you’re having 10–12 ounces [approximately 283–340 grams] of some type of a healthy protein, 30–40 grams of fiber — the carbohydrates could be grains and fruits and vegetables — and some fat, then it will be very filling, it would be very satiating, and it will really help with diabetes,” he added.
Dr. Taylor suggested looking at the Newcastle diet and his own book, Life Without Diabetes.
“But then discuss it with spouse/partner/friends before starting because support really helps during the short weight loss phase,“ he added. “And plan when to start to avoid family events which might make it difficult to stick to. But if [you are] on medications from [a] doctor, do discuss with her or him beforehand.”
“Your diet is always important, as is regular physical activity,” Dr. Axen summed up. “Relying only on drugs will result in increasing need for the drugs over time, and this can worsen your disease.”
“You can improve the quality of your life — diet is not just about how many calories you consume, but about the fiber, plant nutrients, minerals, and types of fat you consume,” she added. “Educate yourself about the care of your body. It’s the only one you have.”
