Weight Loss Medications Work — But What Happens When You Stop?

I was quoted in a recent Herald Sun article highlighting an important reality about modern obesity medications such as Wegovy® and Mounjaro®: many people regain weight when treatment is stopped. Unfortunately, weight regain is often portrayed as a failure of willpower. The science tells a very different story.

Read the article here

Obesity Is a Chronic Disease

Obesity is not simply a matter of eating too much or exercising too little. It is a complex, chronic, relapsing disease influenced by genetics, biology, environment, psychology and social factors.

Medications such as semaglutide (Wegovy®) and tirzepatide (Mounjaro®) help address some of the biological drivers of obesity. They reduce hunger, increase feelings of fullness, improve food cravings and help people regain control over eating behaviours.

However, these medications do not permanently change the underlying biology that predisposed a person to obesity in the first place.

As I explained in the article:

"When a person uses these medicines to treat what is a chronic relapsing condition, stopping them doesn't mean that the biology disappears or the environment changes."

Why Weight Regain Happens

When treatment is discontinued, appetite-regulating hormones and brain pathways often revert toward their previous state.

Many patients notice:

• Increased hunger

• Return of food cravings or "food noise"

• Reduced feelings of fullness

• Greater difficulty maintaining healthy eating patterns

As a result, weight regain is common. This is not a lack of motivation or discipline. It reflects the body's natural biological drive to defend its previous weight.

The same principle applies to many chronic conditions. Blood pressure often rises when blood pressure medication is stopped. Blood sugar levels increase when diabetes treatment is withdrawn. Obesity is no different.

The Importance of Protecting Muscle

Another important point raised in the article is body composition. Weight loss is not just loss of body fat. Some muscle and other lean tissues may also be lost during treatment, particularly if protein intake and physical activity are inadequate.

This is why we emphasise:

• Adequate protein intake

• Resistance training and strength-based exercise

• Regular monitoring

• A multidisciplinary approach involving doctors, dietitians and exercise professionals

Our goal is not simply to lose weight. It is to improve health while preserving muscle, strength and physical function.

Weight Management Is More Than Medication

Medications are powerful tools, but they work best when combined with:

• Sustainable nutrition strategies

• Physical activity

• Sleep optimisation

• Behavioural support

• Long-term follow-up

Successful obesity treatment is rarely about a short-term intervention. It is about creating a plan that can be maintained over time.

The Take-Home Message

Weight loss medications are among the most effective obesity treatments we have ever had. For many people they can be life-changing.

However, they should be viewed as obesity management medications rather than temporary weight-loss drugs.

Before starting treatment, it is important to understand that obesity is a chronic disease and that long-term management is often required. Stopping treatment may be appropriate for some people, but it should ideally occur as part of a structured plan with medical support.

The aim is not simply to lose weight. The aim is to improve long-term health, reduce complications and help people live healthier, more fulfilling lives.