CBT for Weight Management: Why Exercise Is Essential for Weight Loss and Maintenance

Deborah Beck Busis, Director, Beck Institute Weight Management Program

A recent study, Impacts of Early Psychological Changes on Correlates of Weight-Loss Maintenance, by Annesi, Powell, and Stewart, aimed to pinpoint the psychological factors during the early stages of treatment that predict long-term success in losing weight and sustaining weight loss in obese women. The participants were assigned to either a cognitive-behavioral treatment group focusing on self-regulation skills or a standard information/education group. Participants were followed across a 12-month period, broken into a 6-month weight-loss phase and a six-month maintenance phase. 

The clinical implications of this study are clear. While changes in diet are essential for initial weight loss, maintaining that loss hinges on maintaining physical activity, and early psychological interventions that include enhancing self-regulation skills, increasing self-efficacy, and improving mood will help cement sustainable exercise routines. Because of this, education-only programs are likely not enough to help people sustain any changes made in the initial six months.   

We have seen this same development in our work with clients.  While we knew that for most people, exercise is not critical for weight loss from a strict calorie-burned perspective, it is absolutely essential in terms of the big picture of weight loss and maintenance for the following reasons: 

1. Exercise helps regulates mood and decreases the need for emotional eating, which impacts how much someone eats. We find that in the absence of helpful coping mechanisms, clients initially turn to food to fill their needs for pleasure, emotional regulation, stress-relief, and entertainment. When these needs are met through physical activity, it becomes much easier for them to reduce extraneous eating.
2. When people gain the skills that enable them to start exercise regularly, it significantly increases their sense of self-efficacy across the board. They prove to themselves that they can do hard things, and they can be consistent, which makes doing other things they’ve previously struggled with (like sticking to a food plan) seem more achievable. We often see a new identity emerge: “I am someone who sticks to my exercise plan, even when it feels hard to do so (and I’m always happy that I do!)” Over time this identity expands to include “I am someone who sticks to my food plan even when it feels hard (and I’m always happy that I do!)” 
3. We also have found that for many people, exercising helps activate their “health mode” and makes it easier for them to continue to make decisions that are in line with their health goals. The opposite is also often true, when clients skip a planned exercise session, it’s a message to their brains that they’re not prioritizing health that day and they often continue to make decisions that aren’t in line with their health goals.    

In addition, exercise while individuals are losing weight is also important. Exercise, especially strength training, helps preserve and even build muscle, so the weight loss is primarily fat rather than muscle.

Beth, a 45-year-old health care professional, came to us because she was eating poorly and not exercising regularly, despite wanting to make changes. She reported difficulty maintaining any form of regular physical activity, despite understanding its benefits. Her past attempts to start exercising often ended within days, reinforcing a belief that she “just wasn’t the kind of person who could stick with healthy habits.” 

We worked with Beth to identify and challenge the unhelpful beliefs and cognitive distortions that were keeping her stuck. One of the first was her all-or-nothing thinking around exercise: If she missed a day, she saw it as a failure. She also thought that if she couldn’t fit in at least 45 minutes on any given day then it wasn’t worth doing anything. Through cognitive restructuring, she learned to replace her unhelpful thoughts with thoughts like “I’m human, I’m allowed to make mistakes and miss a day. I’m just not allowed to use that as an excuse to miss more,” and “Any amount of exercise counts. Anything is better than nothing.” 

Using behavioral activation strategies, Beth started with small, achievable goals. She tracked her progress and reflected on her thoughts and feelings before and after each exercise session. She was quickly able to see that no matter how she felt before she started, she always felt better after she was done. As she noticed the mental and physical benefits of exercise, her motivation grew.

Over the course of three months, Beth developed a consistent exercise routine, eventually walking or doing light cardio five days per week. More importantly, she reported a significant increase in her sense of self-efficacy. She no longer saw herself as someone who “always quits,” but rather as someone capable of setting and achieving goals. 

This new self-perception carried over into other areas: Beth began cooking healthy meals at home, reduced her alcohol intake, and resumed regular medical checkups she had avoided. With each small success, her confidence and mood improved, creating a positive feedback loop. 

This case illustrates how teaching CBT techniques can break cycles of negative thinking and avoidance, enabling clients to take small, manageable steps toward long-term behavioral change. For Beth, learning to shift her mindset around exercise was the first domino that led to broader health improvements and a renewed belief in her ability to change. 

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Reference:

Annesi, J. J., Powell, S. M., & Stewart, F. A. (2024). Impacts of early psychological changes on correlates of weight-loss maintenance: Seeking increased precision for sustained behavioural obesity treatment effects. Health Promotion Journal of Australia. Advance online publication. https://doi.org/10.1002/hpja.911