There is no question that going keto really works. This strict high-fat/low-carb diet denies the body glucose as a main source of energy and instead promotes the production and use of ketone bodies as fuel. It’s a great way to move you off a weight plateau, gain willpower, and get results fast. But going keto also often results in gastrointestinal discomfort, low energy, and moodiness-known as the “keto flu”-which makes the diet and its proven results hard to sustain.