The evidence is compelling. See for yourself here.
I was never a believer in the low-fat diet. It just did not sit well with me. While sugar, well, don’t get me started on this subject. Check out the graphs, especially number 2, 4 and 6.
Comparing the metabolism of fat versus carbohydrates, you can see that they take very different paths. Carbohydrates convert to glucose and the body uses it for energy with help of insulin. Insulin is a hormone manufactured in the body in proportion to carbohydrate intake. To cut the long story short, overconsumption of carbs, can lead to insulin resistance, obesity and diabetes.
Fat can also be used for energy by the body. The mechanism is different, though. Body will convert it to ketones and use that for energy. However, you need bile to break down the fatty acids. Bile is produced by liver in small quantities and stored in the gall bladder. If you eat more fat than you can metabolise, it will pass out with the feces. This is easily checked – the poo will float. So you can’t really overdose on it.
This is a very simplistic explanation, but it works for me. Now, where’s my butter gone?