Check out Dr Jennie Brand-Millers explanation in the latest Gi News from Sydney University.
In a nutshell: long term use (more than 6 months) appears to increase risk of heart disease through a larger intake of saturated fat and provoke kidney problems and bone loss in diabetes.
Low carb diets lack the vitamin and minerals found in carbohydrate foods such as B-group vitamins and so she recommends a supplement.
Other studies have found low carb diets lead to a reduction in soluble and insoluble fibre, which is linked to increased risk of colon cancer.
Jenny recommends a low Gi carb diet which has sufficient nutrients to generally not require supplementation and is a lot more palatable due to an increased range of food.
It’s the last article in the newsletter found at http://ginews.blogspot.com.au/