I’m sure many people found last week’s headlines on weight loss and hormones discouraging. The message: failure to maintain weight loss is due to hormonal changes, not lack of willpower.
According to the study, published last Thursday in the New England Journal of Medicine, such alterations in hormone levels work against you by revving up appetiteand decreasing calorie-burning for at least a year after losing excess weight. A perfect recipe for weight regain.
The findings strongly suggest something health professionals have long been saying: it’s better to prevent weight gain in the first place than try to battle the bulge once the pounds have piled on.
Earlier research has revealed that during calorie restriction and weight loss, hormonal changes occur that slow metabolism and increase hunger. But whether these changes persist is not known. If they do last, it could explain why so many people in weight-loss programs regain most of their lost weight – and sometimes more – within 3 to 5 years.
In last week’s study, researchers from the University of Melbourne set out to answer that question. They enrolled 50 overweight or obese but otherwise healthy adults, whose average weight was 209 pounds, in a 10-week weight-loss program.
The diet was strict – 500 to 550 calories a day using a very low-calorie meal replacement called Optifast supplemented with vegetables.
During weeks 9 and 10, individuals who had lost at least 10 per cent of their weight – the target – were gradually reintroduced to normal foods. (Ultimately, only 34 participants stuck with the study or achieved the required weight loss.)
Weight loss averaged 29 pounds and, as expected, levels of appetite-related hormones changed in such a way as to increase hunger and slow metabolism.
After 10 weeks, successful dieters received one-on-one counselling and written advice from a dietitian on a diet that would allow them to maintain their weight loss. They were also encouraged to get 30 minutes of moderate to intense exercise most days of the week.
During the maintenance phase, participants checked in at the clinic every two months and were contacted by phone between face-to-face visits for ongoing counselling.
Despite the maintenance diet, the subjects gained back roughly half of what they had lost over the next year.
The key finding was that, after one year of maintenance, the levels of six hormones remained altered in a direction that would boost appetite. The dieters also reported feeling hungrier after the 12-month mark than they did at the start of the study.
The researchers speculate this biological urge to eat – a hormonal response triggered by weight loss – has an evolutionary basis. Such a response would have benefited a lean person in times when food was scarce. But in modern times when high-calorie food is accessible 24/7, these compensatory hormonal mechanisms promote weight regain.
So what to do? Abandon your attempt to lose weight thinking it’s futile anyway? In my opinion, that’s not the answer. In my private practice, I have helped many clients lose and successfully maintain their weight loss.
I am not suggesting hormonal changes that increase appetite don’t occur with weight loss. The science says otherwise.
But we don’t know whether following a higher calorie weight-loss diet that’s less restrictive – and one that’s much easier to sustain for the long term – causes the same hormonal changes thought to promote weight regain. It’s missing information that this study team hopes to provide through their ongoing research.
In the meantime, short of developing safe and effective medications that would counteract appetite-related hormones, there are strategies that can increase the odds of long-term weight-loss success.
According to a 2010 study, also published in the New England Journal of Medicine, you stand a better chance of keeping the pounds off for good if you eat a higher-in-protein diet that contains low glycemic-index (GI) carbohydrates.
Meals that include low GI foods are thought to cause changes to hormones and metabolism that can reduce hunger and prevent overeating. Low GI foods include beans, lentils, nuts, pasta, brown rice, sweet potatoes, steel-cut or large flake oats, oat bran, Red River cereal, 100-per-cent bran cereals, yogurt, milk and unflavored soy milk, apples, oranges, peaches, pears and berries.
Protein-rich foods such as lean meat, poultry, fish, eggs, tofu and dairy products delay the rate at which food is emptied from your stomach. In this way, including protein at meals lowers the GI further and keeps you feeling full longer.
But you also need to stay focused on your goal: maintaining your loss. After you’ve hit your weight goal, it’s easy for portion sizes to increase, extra snacks to sneak in and the motivation to work out to wane.
Permanent weight loss requires weighing yourself regularly. The National Weight Control Registry (NWCR), an ongoing U.S.-based study tracking over 5,000 people who have successfully lost significant amounts of weight and kept if off for long periods of time, reported that 75 per cent of participants weigh themselves at least once a week.
Checking in with the bathroom scale allows you to correct small increases in weight quickly. A key to long-term weight maintenance is nipping small weight gains in the bud – before they accumulate.
Regular exercise is important too. Ninety per cent of successful maintainers in the NWCR report getting one hour of scheduled exercise each day, most often brisk walking.
Physical activity burns calories and helps reduce stress, which otherwise might lead to overeating. Regular exercise also boosts self-esteem, a positive feeling that’s linked to making healthy food choices.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV’s Canada AM every Wednesday. Her website is lesliebeck.com .