Well that seems confusing - so which one is it? Let me explain.
Diets sell you success over a few weeks or a few months. I am not going to lie - they do work.
But when people want to lose weight they are not saying they want to put it all back on again but that's what happens. And so begins the cycle of yo yo dieting.
Maintaining the new weight needs to be considered over at least 1-2 years post diet because the studies show this is where weight gain begins.
The reason to think about ditching your diet and putting a focus on your health and your habits is not because diets don't work (because we know they do) it is because when we promote health first, we want to reduce the risk of other outcomes related to dieting - psychosocial and behavioural factors. No sense going on a diet if it's going to break you mentally or cause another problem.
All qualified health professionals look first at risk versus reward and losing weight should be no different.
I certainly don't want my clients developing severe anxiety, depression, low self esteem, low self worth or eating disorders Most come to me because they believe weight loss will improve health, and for many it does but we put a focus on the overall health aspect, not the weight loss.
That can sometimes mean dealing with anxiety, depression, low self esteem, low self worth perfectionism or eating disorders first!
When we look at the studies into long term weight maintenance we see that weight gain after a diet usually starts to happen within the first year of "coming off" the diet. And if weight starts to increase then it carries on doing so gradually. Over 1 year, 2 years, 4 years........ it seems to keep going up.
However, if you diet and manage to maintain the new weight for over 1 year and more so for 2 years, then there is a 50% lower chance of weight regain and at 5 years there is a 71% lower chance of weight regain.
Simply put, whatever happens in the first year after stopping a diet is probably what your long term outcome will be.
In early behavioural research it has been shown that people who were already struggling psychologically before trying to diet were the ones who gained weight immediately after stopping diets. These people already struggled with high dietary restraint, were depressed or were disinhibited.
Behaviour correlates the outcome - not the diet, and one of the main drivers of success is psychological flexibility and strength.
Trying to succeed from a place of control and rigidity doesn't work psychologically and it doesn't work when dieting either, as we know higher levels of restrained eating (dieting) leads to more weight gain long term.
People who are willing to seek help and support and understand the long term nature of losing weight (i.e. weight maintenance) do best. In the Look AHEAD study they showed that the people who were most engaged, with the highest number of "in person" contact with psychologists, dietitians, docs etc did best. They worked on their nutrition, their fitness, their mental health and accepted social support.
Behavioural, social and psychological support drives the success rates rather than what you eat.
This is also shown in the National Weight Control Registry.
The NWCR keeps tabs on those who maintain a weight loss and it also shows that flexibility in behaviour and development of healthy habits such as eating a densely nutritious diet and maintaining an active lifestyle are key to long term maintenance - of at least 5 years and even over ten years.
What it also tells us is that of the 10,000+ people it monitors they didn't all follow the same kind of diet to lose weight and they don't follow the same diet to maintain it.
So in a nutshell Any diet can help for weight loss but if you want to maintain it - habit and behaviour need A LOT of work and that work may need done before attempting a diet.
People will often say "it's not a diet, it's a lifestyle change" but they fail to realise what that entails in terms of the psychological aspects of habit formation and behaviour change.
People CAN lose weight on a diet but a diet isn't the answer to long term weight maintenance.
Psychological strength & flexibility plus a high level of self efficacy is required to cope with the demands of a weight loss diet and the long term maintenance afterwards.
A high level of behaviour change and support is required for a number of years for successful long term maintenance.
Increase in positive behaviours slowly over time is required for habits to stick.
Reduction in sedentary behaviours correlates most closely with long term maintenance.
It is likely to take 2-5 years for all of this to happen when there has been a long term struggle to control weight.