It is often said that 95 percent of weight-loss measures don’t work. Only, it’s not true. Advances in behavioural treatments (such as cognitive behavioural therapy) for obesity and weight-loss drugs mean there are lots of approaches that help people lose weight.
In fact, weight loss is the easy part (relatively speaking). The problem is that when you come off a diet or stop taking a weight-loss drug, the weight will invariably creep back up.
To be clear, this does not mean that diets and other obesity treatments are useless. Far from it.
In a recent study, published in Lancet Public Health, researchers checked in on participants five years after they took part in a 12- or 52-week WW programme (formerly called Weight Watchers).
Although, on average, people’s weight had crept back up, some weight loss – about 2 kilograms, on average – was sustained for up to five years.
Even this short time at a lower weight can substantially reduce a person’s lifetime risk of developing diabetes, heart disease and other weight-related diseases. But for people with obesity, and their healthcare providers, weight regain can be demoralising.
The stigma surrounding obesity, which views a person’s weight as their responsibility, means that this ‘failure’ of treatment is often felt as a personal failing. This is not true. So why does the weight come back on?
Your brain doesn’t want you to lose weight
There are a few reasons why the weight creeps back on. First, our brain hates it when we lose weight. It considers this a reduction in our chances of survival, so it does everything in its power to drag your weight back up.
As you lose weight, your brain reduces your metabolic rate (the rate at which your body burns calories), making you subtly more efficient. The reality is, if there are two people of identical weight, one weight stable and the other having just lost weight, the latter will have to eat less food to remain the same weight.
It turns out that a hormone secreted from fat called leptin is largely responsible for this. One of leptin’s key roles is to let the brain know how much fat you are carrying. The more fat you have, the more leptin is produced. So when you lose weight, your brain senses the corresponding drop in leptin.
What is exciting is that scientists have shown that if you administer just enough leptin to fool your brain into thinking you haven’t lost any weight, then many …….