For decades we’ve been told that weight loss and healthy eating demand discipline, rules and sacrifice. Most diets reinforce this idea, urging us to cut carbs and banish sugar. The message is clear: good health requires strict regimes, and a single slip-up will undo your progress. But a growing body of research suggests that flexibility, not restriction, may be the real key to long-term success.
A new study by the University of Illinois Urbana-Champaign found that having a little bit of what you fancy might be the optimal strategy for losing weight, keeping it off and reducing cravings.
In the study, published in the journal Physiology and Behavior, participants who allowed themselves small portions of foods they craved as part of a well-balanced diet lost significantly more weight over the course of one year, and reported larger reductions in cravings (especially for sweets and high-fat foods such as hot dogs and fried chicken), compared with those who did not use this “inclusion strategy”.
“Many people think that if you want to lose weight, you need to have strong willpower and resist the temptation for certain foods,” says the study’s lead author, Professor Manabu T Nakamura. “That’s not the case. It’s about sustainability. If you want to make a change stick, it has to be rewarding — otherwise you simply won’t do it.”
Most diets, Nakamura notes, fail because people can’t keep them up. “No food is banned,” he says. “If you can incorporate it wisely and the overall meal is balanced, that’s fine.”
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This idea that having a flexible diet is beneficial for weight regulation is backed up by other studies. These have found that adopting a flexible approach to food is inversely correlated with body mass index, and that rigid control over one’s diet is linked to higher body weight and greater disinhibition — the tendency to overeat when faced with highly palatable foods or in response to stress.
While weight-loss jabs have been a lifeline for some people, willpower and “a little bit of what you fancy” could be a more sustainable approach for others.
“Flexibility is essential as life is unpredictable,” says the dietician Sarah Anzlovar. “When your eating relies on strict rules, it only takes a stressful day, sick kids, a vacation or a spontaneous dinner out to throw everything off.
“When that happens, people often feel they’ve failed, which can lead to what I call ‘revenge eating’, either as an act of rebellion against restriction or a Last Supper-style binge before they vow to be ‘good’ again. This all-or-nothing mindset turns a single cookie into an entire box, because your brain says, ‘You already messed up — you might as well keep going.’ ”
What does balanced eating look like in practice? The key is to eat a broadly healthy diet — one rich in whole grains, fruits and vegetables — and then allow yourself the occasional treat. Some people frame this as 10-20 per cent of their daily calories: a discretionary allowance you can spend on whatever you like. At 186 calories, a Cadbury’s Crunchie, for example, would be fine for most people given the average daily intake for a man is 2,500 calories and a woman 2,000.
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“I would be careful not to put a number on it,” says the dietician Priya Tew. Attaching a specific number can be impractical and, for some people, may fuel a new form of perfectionism — the pressure to hit the “perfect” balance.
The absence of rules takes much of the power away from food, Tew says. After all, “It’s just food.”
“Don’t create a diet that you don’t like,” Nakamura says. “Our approach is not just about weight loss but about maintaining that weight loss. If you don’t like what you’re eating, you’ll never sustain it.”