If you’re like millions of others around the UK and the world, 1 January marked a day on which you committed anew to lose weight, and you are now engrossed in your latest weight loss programme. You are hopeful that 2015 really will be different and you’ll be able to (finally!) lose weight and keep it off. You may feel desperate to find a weight loss strategy that actually works, but with so many contradictory claims and theories, which weight loss interventions have been proven to work?
One recent Canadian study set out to examine just that. A systematic review examined 67 studies on various weight loss interventions, and determined whether they were successful or unsuccessful. A “successful intervention” was defined by one that achieved at least 5% weight loss, on average. And maintenance was successful if the weight was kept off for at least one year. Researchers then looked at the successful interventions to see what they had in common. Here’s the scoop:
Eat to live, don’t live to eat
The research showed that (although it may seem obvious, we feel it’s worth stressing) in order to lose weight you do need to eat fewer calories, and you should record your calorie consumption with a specific goal in mind. The studies showed that to achieve safe weight loss, an energy deficit was required, with a minimum of 1,200 calories for women and 1,500 calories for men to achieve safe weight loss. (Note that eating less than this could be harmful to your health and was not recommended). A reduction in fat was a component of most interventions to achieve this, and 21% of the successful interventions asked participants to increase the amount of fibre consumed. (High fibre foods include lentils, beans, oats, wheat bran, wholegrain cereals, and brown rice, as well as all fruits and vegetables). It seemed important to actually measure and record how many calories were being consumed, with clear goals in mind. Indeed, the studies that used less strict measures (such as focusing on healthy eating instead of calorie restriction) were unsuccessful (eg they achieved less than 5% of weight loss).
Get your groove on
An impressive 23 of the 24 studies that reported successful weight loss had components of physical activity in their interventions. In most of these studies, a weekly time goal was prescribed with a suggested number of sessions per week. The goals ranged from walking up to 150 minutes per week to moderate physical activity for 150 or 200 minutes per week, or aerobic activity of 180, 225, 240, or 280 minutes per week. Physical activity was also defined by energy expenditure goals (such as 1,000 to 3,000 calories per week). The upshot: monitored physical activity is an important factor in successful weight loss. Indeed, studies that were unsuccessful either lacked physical activity intervention (eg they advised dieting but not exercise), or lacked monitoring (it seems important to have exercise goals and to record them, not just adopt the vague idea that one should exercise more).
Train your brain
Like physical exercise, behavioural training was a component of the vast majority (22 of 24) of the interventions that demonstrated significant weight loss. Techniques included standard behavioural therapy, cognitive behavioural therapy, general education on behavioural strategies, stress management or interactions with health professionals (psychologists, health coaches, or a registered dietician). While a variety of techniques were used, the most frequent was keeping a diary of some aspects of the program (eating, activity, behaviours, or weight). Social support, goal setting, and motivational techniques were other methods used. While behavioural techniques may not seem as important as diet and exercise, the researchers commented that self-monitoring and cognitive strategies “represent a critical factor in long-term behaviour change.”
What about keeping weight off?
As most dieters are aware, losing weight is one thing, but keeping it off is a whole other ballgame. Of the studies examined in the review, 24 examined weight maintenance after weight loss, and 10 focused on weight maintenance alone. What did they find?
Get off to a great start
One interesting finding from the successful maintenance studies was that the initial weight loss program was “very comprehensive.” It seems that the knowledge and skills gained from the initial dieting period during which weight is lost carry over into weight maintenance. To put it another way, when participants worked hard to change their behaviour in the short-term, it paid off in the long-term.
It can’t be a Monday-Friday thing -- commit to consistent, long-term lifestyle changes
Many studies discussed the importance of diligence in maintaining long-term change. For instance, in one intervention, keeping weight off was associated with dieting consistency (as opposed to being less strict on weekends or holidays). In two other follow-up studies, participants who had successfully kept weight off had low energy intakes (averaging 1,381 calories per day), low fat intakes (24% of overall calories), and high activity levels (burning 2,827 calories per week). Successful individuals were also more likely to have regular meal patterns, weigh themselves daily, and drink more water. They were also less likely to binge eat, drink sugar-sweetened beverages, consume sugary and fatty foods, and drink large amounts of alcohol.
While we’d all love a “quick fix” in weight loss, this review confirms the importance of lifestyle changes, both for weight loss and weight loss maintenance. Indeed, the interventions that were most successful (averaging 8-10% weight loss maintained over time) had a three-pronged approach: 1. defined calorie reduction; 2. defined physical activity; and 3. behavioural techniques including self-monitoring and professional support.
Another important finding was that what works to lose weight is exactly what works to keep it off. The diet, physical activity, and behavioural techniques looked identical between the weight loss phase and the maintenance phases of the successful programs. Unfortunately, it seems that the fantasy that you can go on a temporary diet to lose a large amount of weight and then return to your pre-diet behaviours (while keeping the weight off) is just that—a fantasy. We think this is a great reason to avoid unpleasant crash diets, exercise you hate, or any approach that you’ll be unable to sustain for a lifetime. We all need to think of weight loss as a permanent lifestyle shift. Embrace the fact that you will have to eat less not just for a short period, but for good. Find exercise you genuinely enjoy and set goals for yourself each week. Make use of behavioural techniques that really help your mind get in the right place for weight loss.
While there may not be any magic bullets, the rewards of this kind of weight loss are great and we have a feeling they’re not just related to what the scales show, but have something to do with a real sense of achievement, self-confidence, self-discipline, and a sense of control over your own life. Now those are New Year’s goals that are certainly worth toasting.
Ramage S, Farmer A, Eccles KA, McCargar L. Healthy strategies for successful weight loss and weight maintenance: a systematic review. Appl Physiol Nutr Metab. 39(1), 1-20 (2014).