The rate at which diets fail can be blamed on bad information as much as bad habits. You can be completely driven towards your fitness goals and have a willpower of steel, but if you are unknowingly doing something to mess up your diet, it will only end in frustration. Here are some are the most common misunderstandings and mistakes that trainers make while dieting.

One major mistake is following prescribed diets to the letter. While a diet that is laid out in a magazine or on a website might be ideal for some people, it can’t possibly factor in your body weight, metabolism, and personal fitness goals. So treat these diets as more guidelines and suggestions than anything else. Tweak them according to whether you want to gain or lose weight and what your body type is. Or better yet, check with a personal trainer to see what diet plan might suit you best.

If you are a bodybuilder looking to bulk up, it’s a terrible idea to just eat as much food as you can stand from every possible source. There’s no denial that bodybuilders looking to pack on muscle have to consume a lot of calories, but it has to be done intelligently. Try and put in a good balance of carbs, proteins, and fats. Also, make sure to eat several times throughout the diet to rev up your metabolism.

Of course, it’s also a mistake to eat too little if you are looking to build muscle. As you gain weight, you need to adjust your diet accordingly to bulk up. Eating too little will force your body to start burning muscle for energy, which will in turn slow down your metabolism and make it harder to process foods.

A lot people get it in their heads that every kind of fat from every source is a fitness killer. Really, in the varied world of fats there’s only one kind people should avoid all the time (trans fats) and one kind they should mostly avoid or eat in small quantities (saturated fats). Other kinds of fats, such as monosaturated and polyunsaturated fats, are important for a well rounded diet and healthy body. Essential Fatty Acids are called “essential” for a reason. Educate yourself on the “good” fats and make sure you add a few to your diet.

No one should ever think that supplements can possibly replace a smart diet plan of whole foods. Getting your carbohydrates and fiber from a pill will just never be as good for you as getting it from a vegetable. Make real food the center of your diet, and only add supplements under the advice of your personal trainer.

But the number one error people make about nutrition has to be thinking that eating right is not as important as working out when it comes to your fitness goals. You could be the biggest gym rat on the plant, squat with perfect technique, and lay out a perfect exercise plan, but it will hardly affect anything if you don’t play close attention to what you are putting in your body. Getting fit is the whole package: eating smart and workout out smart. You can’t neglect either without suffering serious fitness consequences.