Low-fat, low-carb, high-protein, high-fat, high-carb but low-calorie - you've probably heard of every possible permutation of macronutrients as a gateway to weight-loss. Frankly, this is not surprising. Nutritional science has increasingly begun to discover that the optimal diet should be an individualized solution, determined by many factors like genetics and the composition of a person’s gut microbiota. For some, eating less carbs may be the answer, for others - not necessarily.

A recent study from the University of Copenhagen has identified two biomarkers that could predict which diet is optimal for weight loss, especially in prediabetic and diabetic individuals. These markers are fasting blood sugar (fasting plasma glucose - FPG) and fasting insulin. The results of the study were based on three separate trials that included a total of 1200 individuals who were categorized on the basis of their FPG as normoglycemic (FPG <5.6 mmol/L), prediabetic (FPG 5.6–6.9 mmol/L), or diabetic (FPG ≥7.0 mmol/L).  

The results showed that the type of diet (low-carb, high-fat vs. low-fat, high-carb) made a significant difference for individuals who had elevated FPG before treatment and not much of a difference for individuals who had normal FPG levels. For example, in one of the trials diabetic individuals lost a mean of 4.52 pounds more on a high-fat and low-carbohydrate diet than on the low-fat and high-carbohydrate diet, whereas normoglycemic individuals lost a mean of 0.95 pounds more on the low-fat and high-carbohydrate diet. In other words, the effect of restricting certain macro-nutrients will be different in different individuals. Particularly, restricting carbohydrates has a much more beneficial effect in prediabetic and diabetic individuals.

Arne Astrup, M.D., Head of Department of Nutrition, Exercise and Sports at University of Copenhagen said: 

”The beauty of this concept is its simplicity. While we are looking into other biomarkers, it is quite amazing how much more we can do for our patients just by using those two simple biomarkers. We will continue to participate in and support research to explore additional biomarkers such as gut microbiota and genomics approaches, which may offer more insights and help to more effectively customize the right diet for specific individuals."

According to the CDC, more than 1 out of 3 Americans have prediabetes. Prediabetes is a serious health condition where blood sugar levels are higher than normal, but not high enough yet to be diagnosed as diabetes. Prediabetes puts you at increased risk of developing type 2 diabetes, heart disease, and stroke, yet 90% of those who have prediabetes are unaware of it. 

This study once again shows that personalized nutrition based on individual’s biomarkers, rather than following generic nutrition plans, may be the key to achieving better weight loss and maintenance success as well as better health outcomes.