Calorie counting and faddy low-carb diets have lots of difficulties:

1. They are terrible for your hormonal health
   Fat contains cholesterol, which your body converts to steroidal hormones. This includes testosterone as well as estrogen. A diet in which less than 20% of the calories come from fat limits your  production of testosterone and other hormones. You should consume healthy fats, enough fats to maintain hormone production. 
2. You will start calorie counting (not looking for the right calories)
   Calorie counting is generally bad and it takes all the fun out of eating. The evidence that carbs are superior for performance is undeniable, the ketogenic diet (carbohydrate restriction of less than 50 grams per day, favoring high fat intake instead) will require a calculator!
3. Deficiency of micro-nutrients
   If your low-carb diet restricts the amount of fruits and vegetables that you eat, you will not be consuming enough minerals,  vitamins, and dietary fibre. Taking tablet supplements is not the solution to this because the micro-nutrients are not in their natural form.
4. Potential risks associated with high "bad" fat consumption
   Low-carb diets such as the Atkins diet contain large amounts of fat, and numerous studies suggest that higher consumption of fats (particularly polyunsaturated fats) increases your risk of heart disease and other ailments. 
5. Cravings resulting from the elimination of carbohydrate-rich foods
   Any diet that greatly or completely restricts our selection of foods, can lead to increased cravings for the eliminated foods or boredom with the allowable food selections. It is very easy to fall off the wagon and break the diet.
6. Low-carb versions of meals are often processed garbage
   To overcome the restrictions on the low-carb diet, you can opt for low-carb versions of foods from the grocery store. You will end up eating way more processed food that are probably GMO and contains few micro-nutrients.
7. Incompatibility with vegetarian lifestyle
   Nearly all low-carb meal plans focus on the consumption of meats and other animal-based foods.