The Dietary Science Foundation
Telephone:+46 70-750 22 16
269 39 Båstad
There is no sound science supporting the advice for a low-fat diet that has been given to people with type 2 diabetes since the 1970s. On the contrary: a diet with a high carbohydrate content makes it hard for many patients to maintain a low and stable blood sugar. There is an urgent need for high quality studies that evaluate alternative dietary treatments, like a low-glycemic (GI) diet, a strict low-carbohydrate diet and intermittent fasting. Better blood sugar control will increase the life span of afflicted people as well as save enormous healthcare resources.
People with type 2 diabetes have long been recommended to eat a low-fat diet to lose weight and improve their blood lipids. But in the fall of 2012 the largest scientific assessment ever of a low-fat diet in type 2 diabetes was terminated early because the treatment did not show any effect. The risk of developing cardiovascular disease was as great as in the control group. The results were published in 2013 in the New England Journal of Medicine: Cardiovascular Effects of Intensive Lifestyle Intervention in Type 2 Diabetes. Additionally, in a literature review called “Diet and diabetes”, conducted by the Swedish Agency for Health Technology Assessment and Assessment of Social Services (SBU) in 2010, the conclusion was that there were substantial knowledge gaps with no high-quality studies supporting the current dietary advice.
The traditional recommendations for a low-fat diet are based mainly on the goal of lowering cholesterol levels in the blood. However, modern research shows that it is equally important to lower blood sugar and insulin levels. Therefore, there is a need for clinical trials examining the effects of different glucose-lowering strategies, such as a low-GI diet, a strict low-carbohydrate diet and intermittent fasting. The experience of many people with type 2 diabetes is that their blood sugar levels stabilize when they exclude sugar and other carbohydrates from their diet. Small pilot studies also suggest that a strict low-carbohydrate diet can improve blood lipids and blood sugar (see references below). But all of these studies are too small and too short to base new national treatment guidelines on.
The Dietary Science Foundation sees an urgent need for high-quality studies evaluating how people with type 2 diabetes should eat in order to prevent things such as heart-disease, kidney failure and eye damage. Diabetes often shortens people’s lives. In addition, it costs society enormous sums of money. According to the American Diabetes Association, the total cost of diagnosed diabetes has risen by 41 percent in just five years, from $174 billion in 2007 to $245 billion in 2012.
Type 2 diabetes is less common in Sweden than in the USA, but even countries with a low prevalence of diabetes have a lot to gain from more efficient dietary advice. To use Sweden as an example: it has been estimated that diabetes accounts for about 6 percent of Sweden’s health care expenditures. This translates into diabetes costing around 0.5-1 percent of the country’s annual GDP. A pilot study showed that people with type 2 diabetes can reduce their insulin requirements by an average of a quarter if a low-carbohydrate diet is recommended. Insulin drugs cost the Swedish taxpayers about €100 million per year. If just one-fifth of the country’s diabetics reduced their need for insulin by a quarter, it would save the health care system at least €10 million per year.
Studies about the effect of a low-carbohydrate diet on type 2 diabetes:
In type 2 diabetes, randomisation to advice to follow a low-carbohydrate diet transiently improves glycaemic control compared with advice to follow a low-fat diet producing a similar weight loss
The effect of a low-carbohydrate, ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus Low-carbohydrate diet in type 2 diabetes: stable improvement of bodyweight and glycemic control during 44 months follow-up
Effects of a low-carbohydrate diet on glycemic control in outpatients with severe type 2 diabetes Short-term effects of severe dietary carbohydrate-restriction advice in Type 2 diabetes–a randomized controlled trial