Superior Life Keto: Because the ketogenic diet is limited in terms of food groups, you'll be at risk for nutrient deficiencies. "The diet requires a robust supplement regimen, since you can develop certain deficiencies on a ketogenic diet That can inhibit your ability to stay in ketosis," says Jalali. The cons of the Keto Diet"As with any diet, there are always pros and cons," says Devje. The safety concerns with a keto diet are relatively minor, and easily preventable. However, thatisn't to say that the diet is appropriate for absolutely everyone.