Rats Offer Evidence Humans Haven't continued...
"The animals on the high-GI diet were gaining more weight with same amount of food, and we had to cut their food back increasingly over time to keep them at the same weight," he tells WebMD.
"But what was really interesting to us was that even though they maintained the same weight because they got less food, the high-GI group in both rats and mice doubled their body fat and had a reduction ... in muscle mass, which is exactly what you don't want.
"They also had increases in their blood sugars, insulin, lipids, and other disease risk factors, and their pancreas beta cells that make insulin looked like they were going through a scarring process. If continued, that suggests a high likelihood of getting diabetes."
When his team switched the diets midway through the study, and those high-GI-eating rodents were given the low-GI diets, these adverse changes reversed. Meanwhile, the rodents switched from the low- to the high-GI diets started to have the same problems with added body fat, less muscle mass, and signs of impending diabetes.
Processing: The Root of Problems?
What do this mean to you?
Scientifically, it suggests that a low-GI eating plan may be a factor in the amount of body fat and muscle mass a person has and their risk for diabetes. Eating low-GI carbohydrates may not only prevent, but actually treat obesity-related problems. Ludwig is recruiting for a human study on low-GI diets to confirm these rodent findings.
But it also adds more evidence that carbs aren't necessarily the enemy, and you should have them as part of a healthy diet, says Ludwig. "Just as it's too simplistic to think that all fats are bad when, in fact, some are very healthful, it's too simplistic to consider all carbohydrates unhealthful."
The key is to eat those with a low glycemic index -- usually, those in their least processed state. There's no need to calculate your GI index with on-the-web charts, says Ludwig. Instead, just follow that often-preached advice of eating as "whole" as possible.