Breaking Up With Willpower: Why Habits Do the Heavy Lifting on a GLP-1 medication

For most of my life, I thought my problem was willpower. If I could just ‘try harder’ or ‘be more disciplined’, then weight loss would last. Every diet, every programme, every app framed it as a moral failing: if you can’t control yourself, you’re not trying hard enough.

And I believed it. For years.

The irony is that the GLP-1 medications proved that this wasn’t true. Because the moment I started, I realised I didn’t suddenly wake up with a new personality or a stronger will. What changed was simple biology: the noise around food finally switched off.

But here’s where it gets interesting. Even with a GLP-1 medication, willpower still didn’t stick around. By 7pm after a long day, I was still exhausted. And if I was relying on discipline to make dinner or go for a walk, it wasn’t happening. Which made me realise: willpower is the flakiest employee I’ve ever hired.

Willpower Isn’t a Strategy

Let’s call willpower what it really is: a limited resource. It might get you through the morning, but it clocks out long before the day is over. Research backs this up. Studies on decision fatigue show that the more choices you make in a day, the harder it is to make good ones later on. That’s why judges hand down harsher sentences right before lunch and why we’re more likely to grab crisps at 9pm than at 9am.

On a GLP-1 medication, appetite is suppressed, which helps. But you’re still living in the same environment with the same decisions to make. And if every meal, snack and step relies on you having the energy to ‘choose well’, then it’s only a matter of time before decision fatigue takes over.

That’s why willpower is not, and never will be, a long term strategy.

Habits as the safety net

When I think about what’s actually kept me moving forward, it hasn’t been bursts of motivation. It’s been the routines I set up when I wasn’t tired.

The water bottle that’s already filled and waiting in the fridge.
The shoes sitting by the door so I can take the dogs out without even thinking about it.
The protein rich meal plan so dinner doesn’t require a mental debate.

These things look boring. They’re not glamorous. But they mean that when willpower inevitably fails me, the decision is already made.

That’s the difference between habits and discipline: habits reduce the need for constant decisions. They run in the background, quietly making life easier, while willpower is off having a nap.

The Psychology of Automaticity

There’s research to explain this. Psychologists call it automaticity. When we repeat an action in the same context enough times, it becomes automatic - it requires little to no conscious thought. Think about brushing your teeth. You don’t stand there every night weighing up the pros and cons. You just do it.

That’s what habits are: shortcuts for the brain. They save energy. And when you’re already managing work, family, health, and everything else life throws at you, saving energy is priceless.

On GLP-1 medication, you’ve already got the benefit of reduced appetite. Add automatic habits on top of that and you suddenly have a system that’s actually sustainable.

My Own Breakup with Willpower

When I came off Wegovy the first time, I thought I could manage on ‘discipline alone’. I lasted about four weeks before the food noise came crashing back, and within three weeks I’d gained five pounds. It wasn’t the weight itself that bothered me most - it was the realisation that without medication, I had nothing else to fall back on. My routines were still fragile or in some cases, non-existent.

That’s when I knew I needed a new approach. I went back on a GLP-1 medication - this time, Mounjaro. But I also started to focus on the foundations I was missing. And honestly? It wasn’t flashy. It was protein at every meal. It was having a regular bedtime. It was walking the dogs even when I didn’t feel like it. It was learning that ‘boring but repeatable’ beats ‘perfect but impossible’ every single time.

That was the moment I stopped trying to wring results out of willpower and started building them out of habits.

Why Habits Last When Willpower Doesn’t

The beauty of habits is that once they’re in place, they don’t demand your attention. You don’t have to wake up every day and ask yourself, shall I brush my teeth?. You just do it. And over time, the same can be true for drinking water, cooking protein, walking after dinner, or switching off your phone before bed.

That’s not to say they don’t require effort in the beginning - they really do. But the effort is front-loaded. Once the behaviour becomes automatic, it costs less energy to keep it going than to stop. That’s why habits are so powerful: they free up mental bandwidth so you can focus on the things that actually require your attention.

And if you’re on a GLP-1 nedication, that bandwidth is valuable. The medication reduces appetite, but habits reduce decision fatigue. Together, they create a system that doesn’t rely on you being ‘on it’ 24/7.

Building Habits That Stick

So how do you build habits when you’re already tired, busy and stretched thin? The same way you’d tackle anything overwhelming: in small, extremely manageable steps.

Start with something tiny - one glass of water in the morning. One protein rich meal a day. Then repeat it. And once it starts to feel natural, add another layer.

I’ve learnt the hard way that trying to overhaul everything at once just leads to burnout and feeling like a failure, which in time erodes my self-esteem. What works is starting small, keeping it consistent and letting the habit grow. It’s not dramatic, but it’s sustainable.

Life Without Willpower (And Why That’s a Good Thing)

The biggest shift for me has been realising that life doesn’t have to run on willpower. I don’t need to wake up every day bracing myself for a battle with food, energy or motivation. With GLP-1 medication lowering the food noise and habits running quietly in the background, the fight isn’t there in the same way anymore.

And after years of dieting, that feels like freedom.

Because at the end of the day, weight loss isn’t just about numbers. It’s about creating a life that doesn’t constantly drain you. And that life isn’t built on discipline. It’s built on the small, boring, repeatable habits that carry you forward when willpower inevitably walks out.

Willpower Will Abandon You

If you take one thing from this, let it be this: willpower isn’t loyal. It will leave you the moment you need it most. Habits, on the other hand, will stay. They’ll quietly shape your days, reduce the number of choices you have to make, and carry you through the times when motivation is gone.

References

• Baumeister RF et al. Ego depletion: Is the active self a limited resource? Journal of Personality and Social Psychology, 1998.

• Vohs KD et al. Decision fatigue exhausts self-regulatory resources. Journal of Personality and Social Psychology, 2014.

• Lally P et al. How are habits formed: Modelling habit formation in the real world. European Journal of Social Psychology, 2010.

• Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. NEJM, 2021 (STEP 1 trial).

• Rubino DM et al. Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance. JAMA, 2021 (STEP 4 trial).