Fasting plasma glucose predicts dietary weight loss success
Individuals with high fasting plasma glucose (FPG) lost more weight than those who had low FPG in response to a high-fibre, low glycaemic load diet, suggesting that FPG could be used as a biomarker to predict dietary weight loss success and to guide selection of the most effective diet, in particular for those with prediabetes and diabetes, according to studies presented at ADA 2017.
“Remarkably, for many patients, use of these biomarkers can lead to a six- to sevenfold greater weight loss,” said Professor Arne Astrup, Head of the Department of Nutrition, Exercise and Sports at the University of Copenhagen, Denmark.
Based on the “Healthy Weight for Living” study, participants with high FPG levels (≥90–125 mg/dL) lost significantly more weight than those with low FPG (<90 mg/dL) at 24 weeks after starting on a high-fibre, low glycaemic load diet (-9.4 percent vs -4.1 percent; p=0.038). The curves for percentage of body weight change between the two FPG groups started diverging by week 10 and remained so thereafter. [ADA 2017, abstract 75-LB]
The study involved 84 participants who followed a diet intervention with portion-controlled menus comprising 40 g/day of dietary fibre, with 48 percent low-glycaemic index carbohydrates, 27 percent fat, and 25 percent protein for 24 weeks.
By week 24, more participants with high FPG had achieved a 5 percent reduction (79 percent vs 50 percent; p=0.064) and 10 percent reduction of their body weight (36 percent vs 8 percent; p=0.088) compared with the low FPG group. Also, an inverse relationship was observed between FPG and weight loss, although this was not statistically significant (p=0.072).
“Fasting blood sugar is easily measured and our findings suggest that it could serve as a useful measure in advising some patients on the type of diet that is most beneficial for their weight loss,” said senior author Dr Sai Krupa Das from Tufts University in Boston, Massachusetts, US.
In another study ─ the NUGENOB* study which randomized 771 primarily obese participants to a low-fat/high-carbohydrate (carb) diet or the inverse for 10 weeks ─ normoglycaemic participants lost 0.43 kg more body weight from the low-fat/high-carb diet than high-fat/low-carb diet (p=0.03), while participants with diabetes or elevated FPG (≥115 mg/dL) benefited more from the high-fat/low-carb diet (weight loss difference vs low-fat/high-carb diet, 2.04 kg; p=0.07 and 3.06 kg; p=0.02 for the diabetes and elevated FPG groups, respectively). [ADA 2017; abstract A5554]
These findings were supported by the PREDIMED** study which showed that among 1,846 participants randomized to receive high-fat Mediterranean diets, those with FPG ≥115 mg/dL lost significantly more weight than those with FPG <115 mg/dL after 5 years (-1.64 vs -0.19 kg; p<0.001). The Mediterranean diet was supplemented with healthy, plant-based fats comprising either 1L olive oil/week or 30 g mixed nuts/day. [ADA 2017; abstract 78-LB]
Besides FPG, fasting plasma insulin (FPI) was also predictive of dietary weight loss. Among obese individuals with prediabetes (FPG ≥100–125 mg/dL), those with high FPI levels (above 11 mIU/L) lost 7.19 kg more weight when consuming a low-fat diet than a low-carb diet (-6.93 vs 0.26 kg; p=0.004); while those with low FPI levels (below 11 mIU/L) benefited more from a low-carb diet (-16.03 vs -9.94 kg; p=0.084). [ADA 2017; abstract 73-LB]
“[N]o single dietary weight loss/maintenance strategy is appropriate for all individuals,” according to the researchers. “[Our findings] represent a significant step forward in personalized weight management … failure to consider glycaemic status may underestimate true weight loss potential.”