Top 5 Reasons Why Diets Fail

Do you ever wonder why you are not successful at dieting? Here are 5 reasons why your diets may be failing…


#1:  The Word “Diet”

People who are in good shape are not those who went on a diet once—they are people who consistently make good food choices, aside from a few indulgences here and there. Instead of  “going on a diet,” you have to change your way of eating for as long as you want to stay healthy and fit (so hopefully for the rest of your life). Henceforth in this post the word “diet” will be used to mean attempted healthy food habit changes.


#2:  Addiction

Recent research from my lab and others show that brain changes resembling substance addiction occur in rats with a history of overeating sugar. These rats exhibit behavior similar to that of substance addiction—they show strong preferences for environments in which they’ve had sugar before, and exhibit withdrawal symptoms when sugar is removed from their diets (Avena et al., 2008).

Together this research suggests that sugar addiction is a real phenomenon. Few people, however, acknowledge that they may have a sugar addiction. Recognizing that you may be addicted to sugar will ensure you take the necessary steps that all addicts must take to change their behaviors.


#3:  Cravings

Top 5 Reasons Why Diets Is UnsuccessfulThe number one reason people don’t adhere to diets is cravings. Cravings are different from hunger because they are strong urges to eat specific food items, where hunger may motivate someone to eat anything. Some people think cravings are your body’s way of saying you’re hungry. The science says otherwise—a recent study found that when participants were hungry, food cravings actually went down (Lappalainen et al., 1990). People on long-term low-calorie diets also report fewer cravings and less hunger (Harvey et al., 1993).

So cravings may be unrelated to hunger levels—how can one combat them?

The first step is knowing exactly what you are craving. Is it the potato chips in themselves or is it the crunchy texture? Is it the salt? Both? Then try something else salty and crunchy, like lightly salted nuts. Knowing what characteristics you crave allows you to substitute the junk foods you crave with healthy foods.


#4:  Dichotomous Thinking

Research has shown that dichotomous thinking is the number one difference between people who regained the weight they had lost after one year and those who kept it off (Byrne et al., 2004).

What exactly is dichotomous thinking?

Basically it’s thinking in black and white, or thinking in extremes. For example, say someone on a diet eats a piece of cake. They may think “oh well, that wasn’t good but I’ll stop now and continue trying to keep my eating habits healthy.” Someone who thinks dichotomously, on the other hand, might think “oh no I messed up and ate a piece of cake, my diet is ruined, may as well eat this whole cake.” You can see why this kind of thinking is problematic when trying to change eating habits. If you are a dichotomous thinker, try to envision how you’ll end up feeling after a decision. How will you feel if you eat one piece of cake? How will you feel if you eat the whole cake?


#5:  Emotional Eating

Research shows that people who tend to eat in response to negative thoughts and emotions show less weight loss than those who don’t at 6 and 18 month follow-ups (Niemeier et al., 2007). Try to identify when you get cravings.

Do you eat more when you’re depressed or stressed? Or do you tend to eat more at social functions?

Figure out what situations and emotions cause you to eat when you’re not hungry, and be mindful of them. When you experience those stimuli, turn to activities other than eating. Maybe take a walk, do some light cleaning—or anything that you find enjoyable. It has been noted that people who keep weight off report using more problem-solving and problem-confronting strategies (such as asking for help on a difficult project or discussing their feeling with someone who upset them). Those who gained the weight back reported using more escape and avoidance techniques, such as eating and sleeping (Ibid). In order to develop healthy eating habits one must first work on adopting healthy coping strategies.

For more reasons diets fail, and how to avoid these pitfalls, see my book Why Diets Fail (Because You’re Addicted to Sugar).

nicole avena phdNicole Avena, PhD

Dr. Nicole Avena is a research neuroscientist/psychologist and expert in the fields of nutrition, diet and addiction. She has published over 60 scholarly journal articles, as well as several book chapters on topics related to food, addiction, obesity and eating disorders. She recently edited the book, Animal Models of Eating Disorders (Springer/Humana Press, 2013), and she has a book Why Diets Fail (Ten Speed/Crown) released in January, 2014. Her research achievements have been honored by awards from several groups including the New York Academy of Sciences, the American Psychological Association, the National Institute on Drug Abuse, and her research has been funded by the National Institutes of Health (NIH) and National Eating Disorders Association. Learn more at