There are a lot of reasons that people think diets don’t work. While we plan on exploring these ideas in depth over time, here’s the top 10 culprits.

1. Unrealistic Expectations — Expecting to lose too much weight too quickly, or expecting it to change your life in unrealistic ways.

2. Unrealistic or Unsustainable Diets — Fad diets, super-low calorie diets, and diets that are too hard to follow all fall in this category. Sure you’ll lose weight on many of these programs, but only if you can stay on it.

3. Depending on Diet Foods — We’ve already explored artificial sweeteners, and fat substitutes aren’t much better. Many of the things the weight loss industry wants to sell you are not helping you. The only thing that loses weight is your wallet.

4. Not Enough Physical Activity, or Unsustainably High Levels of Exercise — Fat doesn’t melt away, you have to work it off. But on the other hand, you can over-do it.

5. Negating Exercise through Diet — We can easily sabotage ourselves with exercise drinks and “little rewards” for hard work.

6. Insufficient Support from Friends and Family, or Negative Help from them — Oh come on, one little cookie won’t hurt you. Fatty.

7. Failure to Actually Follow the Diet — Either we fail to keep track of what we are eating at all, we underestimate serving sizes, or we flat-out cheat. Either way, it’s not the diet that failed; it’s us.

8. Failure to Change Your Relationship with Food and Your Body — To lose weight and keep it off, you have to seriously look at how and why you got fat in the first place and change it.

9. Making Excuses — We whine about our slow metabolism or suspected thyroid problems, but we don’t actually go to a doctor and try to do something about it. The truth is that we want a socially acceptable reason to fail.

10. Going Back to the Fat Way of Life — After we meet that goal, instead of transitioning to a weight maintenance diet, we return to the way of eating that made us fat in the first place. Or worse yet, we reward ourselves with food.