Low-carb, ketogenic or keto, paleo, vegetarian, vegan… all these diets are becoming increasingly popular, including among people with Type 1 diabetes. What do they actually consist of and what are their benefits? We take a closer look at these diets, some of which have actually been around for a long time.
Low carb diets – keto, Atkins, etc.
The basic principle of any “low carb” diet is to limit carbohydrate intake (starchy foods, sweet foods, fruit, etc.), and replacing them with more fats instead.
The health authorities recommend a daily calorie intake of 40 to 55% carbohydrates, 35 to 40% fats and 10 to 20% protein¹. But low carb diets recommend 70 to 80% fats, 20 to 25% proteins and 5 to 10% carbohydrates (20 to 50 grams of carbohydrates per day). These diets restrict the amount of carbohydrates eaten in order to force the body to use up fats as its energy source.
There are two main types of low carb diets:
The Atkins diet involves drastically restricting carbohydrate intake initially before gradually reintroducing them. It is divided into 4 phases:
– 20 to 25 g of carbohydrates per day until you are within 15 lbs of your target weight
– 25 to 50 g of carbohydrates per day until you are within 10 lbs of your target weight
– 50 to 80 g of carbohydrates per day once you have reached your target weight, maintained for one month
– then 80 to 100 g of carbohydrates per day while you are continuing to watch your weight
The second type is the keto or ketogenic diet, when carbohydrate intake is kept so low that the body enters a state of “ketosis” (production of ketones by the liver to supply energy, in place of carbohydrates). When the number of ketones in the blood remains moderate, this is known as “ketosis”. But if the number of ketone bodies exceeds the body’s elimination capacity, the blood becomes too acidic: this is known as “ketoacidosis”. This is also seen in people with Type 1 diabetes when the amount of insulin in their blood is too low.
People usually follow low carb diets to enable them to lose weight quickly. In people with Type 1 diabetes, low carb diets make it possible to reduce bolus insulin doses because the absorption of carbohydrates is almost nil².
A Danish study also concluded that a low-carb diet (100 g carbohydrates/day) for a period of 12 weeks reduced time spent in hypoglycemia, glycemic variability and weight with no impact on cardiovascular risk factors³.
Gluten-free diets to combat celiac disease
One of the main gluten-free diets is the Paleo diet, which entails eating foods that would have been around in the Paleolithic age and hence eliminates processed food, dairy products and cereal.
Gluten is found naturally in a lot of food eaten daily, particularly in processed food. Consequently, this diet excludes a large number of products, especially cereal-based ones ): pasta, bread, bulgur, etc.
So gluten-free diets can be tricky. If not properly balanced, they can cause deficiencies and hyperglycemia.
However, gluten-free diets may be recommended for people with celiac disease, an autoimmune condition that damages the gut wall and requires a strict diet without any gluten. Studies have demonstrated a link between Type 1 diabetes and gluten intolerance that may be explained by a shared gene and could affect 2 to 8% of people living with T1D.
Vegetarian diets exclude all animal protein. Concretely, this means eating no meat, fish or seafood.
Other similar diets also exist, each with their own specific characteristics (lacto-vegetarian, lacto-ovo-vegetarian, pescatarian, flexitarian, vegan, etc.).
These types of diets are increasingly popular for a variety of reasons: religious, ethical, environmental, but also health-related, to avoid products associated with potential virus outbreaks, the possible harmful effects of meat on general health, etc. There are several aspects to vegetarian diets that make them particularly appealing to people with Type 1 diabetes:
- They encourage people to eat more food high in fiber, which helps to control blood sugar levels
- They are low in saturated fats, which helps to lower bad cholesterol (LDL) levels, blood pressure and cardiovascular risks
¹French National Health & Nutrition Plan
²Bouillet B. & al. – A low-carbohydrate high-fat diet initiated promptly after diagnosis provides clinical remission in three patients with type 1 diabetes – Diabetes & Metabolism – Jul 2019 – doi: 10.1016/j.diabet.2019.06.004.