Older male rats that had eaten a fattening diet did better with blood sugar and gained less weight when they ate 30% fewer calories for five weeks — showing that cutting calories can still help, even after bad eating habits.

When overweight mice eat significantly less food, they lose body fat no matter if their diet is low in carbs, low in fat, or high in protein — the key is eating fewer calories overall.

When overweight mice eat fewer calories, their blood sugar control gets better — but if their diet is very low in carbs, their blood sugar doesn’t improve as much as if they ate more carbs.

Even when rats eat fewer calories, a keto-like diet can still cause unhealthy changes in the liver, like making too much sugar and having trouble breaking down proteins.

In rats, eating a diet super high in fat and very low in carbs for a month leads to higher blood sugar and more fat in the liver—even if they're not eating too many calories.

Rats on a very low-carb, high-fat diet for a month ended up with higher blood sugar and more fat in their livers—even if they didn’t eat more calories. This kind of diet might not be great for liver and blood sugar health in animals.