A couple of weeks ago I noticed my Dad was looking particularly trim. Knowing that he works out regularly I asked him what else he had been doing to get such a dramatic result. “I quit sugar,” he proudly announced as he described how the extra pounds he couldn’t shake had practically flown off him.  

In this day and age where sugar is hidden in almost everything, quitting the ever-temping saccharine ingredient is no small thing. I was impressed. And, as I’ve written about previously, based on the evidence, I’m in favour of any diet that encourages a diet of minimally processed foods. But when I saw Dad on the weekend I couldn’t help but notice that his new diet had been totally abandoned. Dad was back on the soda and magnanimously sharing the frosting-covered buns that he ritually buys from his local bakery on Saturday afternoons with my son. My three-year-old thought it was wonderful. Dad looked a little guilty. He’d had a tough week and admitted that all his good intentions had been completely abandoned.  

I can relate to Dad’s struggle to stick to his sugar-free diet. In my own health journey I’ve had many stops and starts. At different times since I was diagnosed with lupus I’ve purchased new gadgets, gone on diets, signed up for a 40-day programs, and participated in just about anything and everything that promised a health revolution. My efforts would usually pay off in the short-term and I’d feel great, reaping the physical and mental health benefits of the changes I’d made. Of course, I always intended to keep doing whatever it was I was doing, but as time passed, my old habits and behavior patterns would return and I’d end up right back where I started.  

My Dad and I aren’t alone in our struggles to make healthy changes stick. According to research conducted by the American Psychological Association, fewer than one in five adults report being successful at making health-related improvements such as losing weight, starting a regular exercise program, eating a healthier diet, and reducing stress. Among those who study behaviour change this phenomenon is called the intention behaviour gap. As I’ve written about before, even if you really really intend to change your behaviour it doesn’t mean you’ll succeed.  

I’ve dedicated a whole chapter to this topic in my forthcoming book and if there’s one thing I’ve learned from all the research I’ve done, it’s that the reasons for this gap between what we intend to do, and what we actually do are complex. You only need to briefly think about what you’re up against to see why it can be so hard to make lasting healthy changes – cleverly packaged treats calling to you off the supermarket shelves, the constant race against time forcing you to make choices based on speed and ease rather than long term gain, and a To Do list as long as your arm on which “move more” or “eat better” comes after more pressing priorities. In this crazy, busy, time-poor, distracted world, we inevitably slip up, and when we do, we think of ourselves as flawed and weak-willed.  

This was one of the weak spots in my own wellness endeavors. I thought if I could just stay focused enough, if I could will myself to eat better, exercise more and stress less, then I’d get healthier. But time and time again, with the first work deadline, the first headache, the first schedule change or the first emotional challenge, this strategy failed.  

Relying on willpower and self-control as a central strategy in getting healthy is not entirely without reason. Having good self-control can influence your success in life as well as your health and wellbeing. But the evidence shows that self-control alone isn’t the key. While there are proven ways to boost willpower and self control, which you can read about here, it’s likely that they will only have a small impact on making lasting healthy changes.  

Let me put it another way. Imagine there’s a chocolate muffin sitting on your desk. Each time you look up from your computer, you see the muffin. It calls to you, entices you, begs you to eat it. Let’s say that in the course of your day you have looked at the muffin 99 times and 99 times you resisted it. But then, at 3pm when you’re feeling a tad tired and your boss has just given you another impossible deadline, on the 100th time you look at the chocolately goodness and you give in. You immediately feel pleasure, but it’s soon followed by guilt. You think of yourself as a failure.  

In this scenario, you had willpower 99 times out of 100. In fact, I would say you had super powers. As Traci Mann, Professor of Social and Health Psychology at the University of Minnesota, highlights in her book Secrets from the Eating Lab, the problem isn’t that you lack willpower or self-control. The problem is that the muffin was sitting on your desk when you were feeling tired and run down.  

There is also vast evidence demonstrating that our willpower is like a muscle that can get fatigued. This understanding comes from research done by Roy Baumeister from Case Western Reserve University. He devised a foundational experiment on self-control that showed that if people were made to sit in a room in front of freshly baked chocolate chip cookies they were not allowed to eat, they had less self-control in a subsequent problem-solving task. Baumeister called this effect “ego depletion” and believes it reveals a fundamental fact about the human mind – that we have a limited supply of willpower, and that this supply decreases with overuse. The paper has been cited thousands of times and inspired hundreds of follow up studies. In 2010, a team of researchers conducted a meta-analysis (a study of studies) that seemed to confirm that ego depletion is a real and reliable phenomenon but the strength and significance of this study has been debated. Scientists are still trying to work out when, where, why, and how we exhaust our willpower. But while they’re still figuring things out, there is nevertheless a clear message in all of this for us: we cannot rely on our willpower alone if we want the healthy changes we make in our lives to last.  

So if the key to healthy behaviour change is not just about boosting willpower and getting more self-control, what is it? I recently spoke to leading behaviour change researcher Peter Gollwitzer, a professor of psychology at New York University, who explained that in order to make healthy changes last, we not only have to have considerable self-regulation, but we also must have knowledge, intention, as well as motivational and volitional strategies. Gollwitzer is especially an advocate of the power of planning, and I’ve written previously about the research showing that his simple “if-then” planning technique is one of the keys to success. I’m also a fan of changing the environment around me in order to make healthy behavior unconscious (fresh fruit bowls on the kitchen bench, not walking down the candy aisle of the supermarket, that kind of thing) and getting tons of support (from friends, health coaches or medical experts).  

My point here is that whatever changes you’d like to make in your life – whether you’d like to start a regular meditation practice, exercise routine, completely shake up your diet, or quit an unhealthy habit, please don’t set yourself up for failure from the start by relying only on your self control.  

Given that my Dad is an expert at giving up bad habits (he’s successfully given up both smoking and drinking alcohol), I asked him where he thought he went wrong with his quitting sugar endeavors and he replied that he thinks he never really quite believed in the diet. I think Dad’s insight is yet another of the keys to making healthy changes last. We have to believe these things will make a difference, and we have to believe in our ability to make the change.