15. Coconut
For those trying to live on a lower-carb diet, coconut is a blessing. Coconut and its MCT oil (medium-chain triglyceride) encourage the production of ketones in the liver. Ketones are an alternative energy source for the body which it can use instead of glucose and which is even preferential for certain activities.
Raising ketones is not a good idea for those with diabetes as they will already be raised but prior to this, it can be a useful way to wean yourself off of carbs.