A ketogenic diet involves consuming foods that are low in carbohydrate content, so the ketones are produced in the liver, which allow the body to use up the fat cells for energy. There are some surprising foods as well that they should avoid for this diet to be effective. Here are some of the surprising ketogenic diet foods you must avoid. Grapes do contain unhealthy carbohydrates, which could affect the results of your keto diet. Cheese Many people following the ketogenic diet feel that they should only avoid carbohydrates and consuming other foods in minimum quantities is alright. The fat content in cheese can affect the ketosis process in the body and come in the way of your diet, slowing down the results. If you are on a keto diet, you can avoid consuming oats, as they too are quite rich in carbohydrate content, which can affect the ketosis process of the body and come in the way of the keto diet.