Experts emphasize, however, that you shouldn’t go hog- (or butter-) wild with saturated fats—found mostly in animal products—which are linked to increase in LDL and a lowering of HDL. Your focus may be on weight loss, but the keto diet can shed dollars from your wallet, too. For people who are passionate about environmental issues, keto is not exactly the poster child for an earth-friendly meal plan. The keto plan is a diet in the extreme sense—not only does it prescribe what you can and cannot eat, it restricts an entire food group. As a result, it can be hard to stick with, especially over any significant period of time.