In addition to being inconclusive for long-term benefits, a low-carb diet may be risky for certain groups. If you’re pregnant or nursing, following a low-carb diet isn’t recommended (barring gestational diabetes, in which case, consult your healthcare team as to how you should most safely proceed). “Many women who are pregnant find that the thought of eating protein and fat makes them sick,” says Spritzler. If you’re someone who does intense CrossFit-style workouts, a low-carb diet may not fuel you properly, says Schmidt. Last, if you have a history of eating disorders, a low-carb diet (or any eating plan that is restrictive) can be risky, nutrition and mental health experts agree.