Understanding the psychology of weight loss


In this article, we explore the psychology of weight loss, with a focus on why some people lose the motivation to lose weight and what motivates others to carry on.

Most people know the basics of losing weight- that it’s all a game of energy. In order to lose weight, you have to burn more energy than you consume. You do that by getting more exercise and eating less food, avoiding foods with high caloric content.

Yet, most people struggle with losing weight. Some even say it’s the hardest thing to do. Why is that?

The answer lies in the fact that weight loss, as any experienced fitness trainer will admit, has a lot to do with psychology. In order to lose weight, you have to maintain a caloric deficit over a sustained period of time.

The problem is: human motivation levels keep fluctuating and this prevents many people from sticking to their goal of losing weight.

Once you understand how your mind works when you’re trying to lose weight, you can use that information to aid you in your efforts. 

Psychology of weight loss and fluctuating motivation levels

We often decide to lose weight when we’re highly motivated, like when it’s the start of a new year, a month, or a week. You promise yourself that you’ll stick to a diet and follow your workout regimen religiously. You do just that for maybe a week or two. Then your motivation fades and you quit. Then when you’re motivated again, you make plans again… and so the cycle continues.

It may sound counter-intuitive but you don’t necessarily need to be motivated all the time to lose weight. Motivation may get you started but you never know when it’ll ditch you so you cannot rely on motivation alone.

Of course, there are always methods you can try (e.g. listening to motivational songs) to keep your motivation levels up but when you’ve had a particularly bad day, that kind of stuff isn’t likely to work.

Why we go off track

We lose motivation for numerous reasons but a major cause of a loss of motivation is feeling bad. When you’re feeling bad on a bad day and you don’t want to work out, your mind’s like, “Hah?! Exercise? Are you kidding me? We got more important things to worry about right now.”

These more important things could include anything- ranging from worrying about a project that you’ve been procrastinating on or being disappointed that you just binge-ate 10 donuts.

Your mind is more interested in fixing these issues than in trying to motivate you to move your limbs in the gym to reach a goal that you can’t even see on the horizon. 

This is why sometimes you have workout days where you don’t pay full attention to what you’re doing and feel like you didn’t get the best out of the session, even if you did speaking strictly in terms of the number of calories burnt. 

weight loss psychology demotivation

You don’t go to the gym which makes you feel bad because you’re now one step farther from your weight loss goal. To feel better you may then eat junk food which makes you feel worse eventually and now you believe you’ve completely fallen off the track.

That’s where the entire problem lies: believing you can’t reach your goal just because you’ve had a bad day.

Here’s the thing: even if you consistently have one bad day per week where you don’t exercise or eat healthy, you can still lose significant weight if you eat properly and work out for the rest 6 days of the week. Continue this for 6 months and you might be very proud of what you see in the mirror.

Bad days are normal and while they may demotivate you for a day, this doesn’t mean you should be demotivated for weeks. It certainly doesn’t mean that you’ve fallen off the track and should call it quits. 

Losing weight is often a continuous cycle of motivation and demotivation. You only need to make sure that on most days of a week or a month you’re doing the right things. A drop of honey in a sea every once in a while isn’t going to make the whole sea sweet. Eating cookies or pizza every once in a while isn’t going to bloat your belly.

Why you shouldn’t go on diets

Losing weight should never feel like work. There are many unrealistic and impractical things that people do when they’re trying to lose weight. They count their calories, keep weight loss journals, go on meticulous meal plans, and follow carefully planned workout schedules.

Since losing weight is considered to be hard, they think that only if they’re super-disciplined and meticulous will they achieve their goal.

While being disciplined is not a bad thing, you can sometimes overdo it. Life is constantly changing and on some days you’ll be forced to forego your diets, workouts, and maintenance of journals.

If you started out believing that doing these things is important for weight loss then you’ll quickly lose motivation when you’re unable to keep up. A better strategy is to be flexible and not be strict about anything at all. 

As long as you maintain a caloric deficit on most days, you’ll lose weight no matter how you do it. A good way to know that you’re maintaining a caloric deficit is by checking if you feel at least a slight pang of hunger before your major meal. If you do, it’s a good sign and if you don’t feel hungry at all, it probably means that the body has more energy than it requires.

Incorporating more movement into your day-to-day activities is an effective strategy. For example, just going out and taking a walk for lunch instead of ordering food online could make a big difference in your weight over time when you do it every single day.

Progress = Motivation

When you know that the changes you’ve made to your lifestyle have worked and begin seeing the results, you’ll be motivated to continue doing those things. Even if it’s just small progress that you’ve made, knowing that one day you’ll reach your desired weight level can be very motivating.

Again, don’t over-rely on motivation because it keeps fluctuating but do motivate yourself whenever you can. Click pictures of yourself frequently to keep track of your progress.

It can be way more motivating than maintaining a weight loss journal because we’re visual animals. Sharing your weight loss goals with others can also help.1 

They can give you the support you need and you can hang out with like-minded people who won’t let you lose sight of your goal.

Ultimately, losing weight boils down to how psychologically stable you are and how well you manage your stress and bad feelings.2

Invest in weight loss

Investing in your weight loss psychologically and financially can be helpful. After all, when you’ve paid a large sum of money for your gym subscription or for buying whole foods, you’re like, “I better get the most out of it. I better make this sacrifice worth it.” 

In one super interesting study, participants were told that in order to lose weight they have to go through a therapy that involved doing hard cognitive tasks requiring a lot of mental effort.

The therapy was bogus and unrelated to any theoretical framework supporting weight loss. The participants who did the tasks ended up losing weight and even maintained a reduced weight after a year.3

The authors of the study concluded that the phenomenon was the result of something called justification of effort

When the participants did the excruciating tasks that they thought would make them lose weight, they had to justify all that effort to reduce the cognitive dissonance that would’ve ensued if they didn’t lose weight still. So they ended up doing all the right things to lose weight.

Note how the exertion of cognitive effort, in this case, was only a one-time thing. Had they been required to do it consistently over a period of time, they’d probably have deemed all that effort not worth it and called it quits. Exactly what people do when they believe they need to do exceptional things to lose weight.


  1. Bradford, T. W., Grier, S. A., & Henderson, G. R. (2017). Weight Loss Through Virtual Support Communities: A Role for Identity-based Motivation in Public Commitment. Journal of Interactive Marketing40, 9-23.
  2. Elfhag, K., & Rössner, S. (2005). Who succeeds in maintaining weight loss? A conceptual review of factors associated with weight loss maintenance and weight regain. Obesity reviews6(1), 67-85.
  3. Axsom, D., & Cooper, J. (1985). Cognitive dissonance and psychotherapy: The role of effort justification in inducing weight loss. Journal of Experimental Social Psychology21(2), 149-160.