Carbohydrates are found in breads, cereals and other grains, fruit, vegetables and milk. They’re also in ultra-processed fast foods, cakes, chips and soft drinks.
These days, low-carb diets are promoted as a weight-loss solution, to beat heart disease and as better for diabetes. But how do these claims match up with the latest research?
A new review of the evidence found long-term low-carb dieters lost just under a kilo more weight than other dieters. However the review concluded there was no evidence low-carb diets have any additional health benefits.
In fact, if you’re on a low-carb diet, you’ll need to pay closer attention to what you eat to make sure you get enough essential vitamins, minerals, dietary fibre and other phytonutrients.
What did the reviewers investigate?
The Cochrane review included 61 randomised controlled trials (the highest level of evidence) with almost 7,000 adults with excess body weight. About 1,800 had type 2 diabetes. People in the healthy weight range were not included.
The reviewers compared weight-loss diets that varied in carbohydrate content:
- lower carbohydrate diets. This included very low-carb or ketogenic diets (less than 50g of carbs a day or less than 10% of your total energy from carbs) and low-carb diets (50-150g of carbs per a day, or less than 45% of total energy from carbs)
- “balanced” carbohydrate diets (150+ grams of carbs a day, or 45-65% of your total energy from carbs).