There’s a popular idea that eating ‘slow’ carbohydrates will result in weight loss or better weight management while eating ‘fast’ carbohydrates will result in weight gain. Fast carbs are called high-glycemic-index foods, while slow carbs are called low-glycemic-index foods. According to a new peer-reviewed study, the popular assumption about these carbs is wrong.
The idea behind the weight gain/loss myth surrounding fast and slow carbs is that high-glycemic-index foods like white potatoes will cause a spike in blood sugar, therefore leading to a similar spike in insulin, a hormone that plays a major role in weight gain.
Low-glycemic-index foods, on the other hand, are digested more slowly, resulting in more stable blood sugar and insulin. According to a new comprehensive study that evaluated data from 43 cohorts, fast carbs don’t lead to gaining weight nor do they cause any weight loss compared to slow carbs.
The study’s co-author Glenn Gaesser, Ph.D., explained:
This study is the first to definitively demonstrate that fast carbs do not make you fat. Contrary to popular belief, those who consume a diet of high-GI foods are no more likely to be obese or gain weight than those who consume a diet of low-GI foods. Furthermore, they are no less likely to lose weight.
Ultimately, the reseachers found that carbohydrates, whether low-GI or high-GI, can play a role in a healthy diet and that avoiding certain carbs for weight reasons may be pointless. The researchers instead say that dieters should hit the right balance of carbohydrates, which often contain fiber and other nutrients linked to lower disease risk and healthier body weights.