The weight often comes back.
Most fad diets promote a “quick fix” and don’t teach healthy eating plans. They tend to be restrictive, boring, and difficult to follow over the long term. Once the weight is lost, a dieter often returns to old eating patterns and habits, causing him or her to regain the weight which was lost.
You can make yourself sick.
Many fad diets, such as the Soup Diet, may restrict or eliminate fruits, vegetables, dairy products, and whole grains. These foods are loaded with nutrients that are thought to help prevent many chronic conditions.
Reduced athletic performance.
Diets that significantly restrict carbohydrates increase symptoms of fatigue and decrease body energy supplies and endurance. Your body needs carbohydrates for energy, and when you don’t eat enough carbohydrates, your body pulls from your stores, also pulling fluid and electrolytes in the process. Your body then gets rid of fluids and electrolytes. This can cause low blood pressure and decreased performance.
A diet low in carbs also puts your body into ketosis, a condition that is unnatural. Ketosis most often occurs in starvation, but it can also occur if you don’t eat enough carbohydrates. Without adequate carbohydrates for an energy supply, fat becomes the primary energy source and ketones become the means of transportation. You may notice “keto breath” or a funny, fruity smell to your breath.
Kidney stones and gout.
Diets that are high in protein and low in carbohydrates often lead to the formation of crystals, causing kidney stone formation and gout. In addition, diets that are too high in protein may cause an increase in calcium loss, leading to osteoporosis.
Overall, fad diets have a low chance of long-term success and may have harmful side effects. Remember to talk to your doctor or a registered healthcare professional before beginning any diet or changed meal plan.