Marginal Gains in Obesity Management

sharma-obesity-treatment-pyramidIn Providence, Rhode Island, researchers are teaching overweight adults how to get more sleep. The patients are learning the importance of developing regular night-time routines, avoiding alcohol and caffeine before bed, and other basic ‘sleep hygiene’ strategies as part of a study investigating whether getting more shut-eye can lead to healthier eating habits and weight loss. In San Francisco, California, clinicians are sending overweight, low-income, pregnant women to a course in mindfulness, in the hope of reducing stress-related overeating. In New York City, scientists are asking overweight African-American and Latino adults to make one small change in their eating behaviours, such as using smaller plates.

As Emily Anthes, a science writer from Brooklyn, New York, reports in an article in the recent Nature Outlook Supplement on Obesity, these studies are part of a US$ 37-million NIH program on trying to translate the latest basic science on obesity to clinical interventions.

This is timely, given that “traditional” behavioural interventions, relying largely on education to get patients to eat less and move more (ELMM) are rather limited in their effectiveness.

Here Anthes quotes Catherine Loria, a nutritional epidemiologist at the NIH,

“We can get a lot of weight loss, the main challenge there is still keeping the weight off long term.”

Unfortunately, this is where Anthes (like most people) falls into the trap of attributing the weight regain simply to patients’ “failure to change long-term habits“.

In reality, this is hardly about “habits”. As regular readers may appreciate, the single most important reason that people regain weight is because of the physiological changes that, rather effectively, counteract people’s weight loss efforts. (To a lesser extent, I would concede that the weight also tends to come back because many behavioural interventions really do not change the underlying drivers of what led to weight gain in the first place, e.g. the food environment, psychosocial stressors, comorbidities, or medications – not to mention genetics).

The reason that I think the physiological changes that oppose weight-loss maintenance are more important than the environment as a driver of weight regain, is because I have yet to see a study suggesting that changing the environment does anything to make weight-loss maintenance more effective in the long-term (plenty of anecdotes but no good science on this).

Although, Anthes quotes a number of researchers who appear optimistic about behavioural approaches to obesity management (e.g. teaching kids to delay gratification), in reality, success has been limited.

This is why there is some excitement about new approaches that focus on the sleep issue.

As Anthes notes (and regular readers of these posts are well aware), epidemiological studies have revealed that children and adults who sleep less tend to weigh more, and sleep deprivation can alter the levels of hormones involved in metabolism and appetite. Interventions studies on sleep duration in kids have shown that spending an extra hour-and-a-half in bed leads to eating 134 fewer calories a day, on average

Other researchers are studying the power of positive thoughts. Here Anthes quotes work by Leonard Epstein showing that overweight women who were asked to think about positive events in their future — such as vacations, birthdays or holiday celebrations — consumed fewer calories during a 15-minute snacking session.

Anthes also discusses studies in low-income groups suggesting that a “Healthy Habits, Happy Homes” approach involving health coaches may be somewhat effective.

Given these “marginal gains”, Anthes correctly notes that some experts (me included) believe that the only practical solution to the obesity problem (at least for the majority of people) will involve drugs.

Of course, any such drugs would need not just be proven to be effective but also safe. While past obesity drugs certainly have a rather spotty record, the sensitivity of regulators to the issues of safety and the ever-increasing demands for data from large randomized-controlled interventions trials prior to approval of new medications will hopefully change this picture.

This does not mean that behavioural interventions will not remain important – they certainly will always be as (but not more) important in managing obesity, as they are in managing any other chronic disease (e.g. diabetes, hypertension, depression, etc.).

Toronto, ON