I’ve been struggling a bit with the New England Journal of Medicine article I wrote about this past Friday. Namely this statement:
“Small, sustained changes in energy intake or expenditure will produce large, long term weight changes.”
During the weekend I thought about articles I have read, research I have reviewed, and talks I have given. One of the recurring themes is that we must make small and meaningful changes in our environments if we have any hope of weight loss. My fear was that, based on the recent article mentioned above, I have been way off base and have been barking up the wrong tree. Then I kept thinking. There are several reasons I lean towards disputing their take on the data. Quickly, here are a few:
1). Small changes may not appear to impact weight loss in research studies because most research studies aren’t able to discern these small changes. They rely on self reporting and we know what means.
2). Speaking of means, maybe that’s the issue. We focus on the mean (average) of the data when we should be looking at the distribution of the data.
3). Most research studies don’t last very long therefore they don’t capture the true outcomes of the small changes.
This mean seem like a rationalization, refuting evidence that I believe in. However, in a recently published article in the journal Appetite, Matthew Schubert and his team reviewed the research on acute exercise and subsequent energy intake. Across many studies, covering the range of exercise intensities and durations, they found that energy intake isn’t increased after we exercise. That is, we don’t compensate for our exercise with increased eating. More importantly they discovered that versus controls those individuals that exercised produced an average caloric deficit on the order of 490 calories. That is a wonderfully large number. But remember, this review looked at acute exercise, not long term.
Data from the National Weight Control Registry demonstrates that those individuals that have lost more than 30 lbs and kept it off for more than a year exercise daily and religiously monitor their food intake. Small changes that add up. The NWCR provides a rare look into what real people have really done and been successful with in terms of weight loss.
Think of it this way: if we could create a daily deficit of 490 calories and continue that deficit indefinitely, I believe the data on how important small changes are would begin to accumulate. If we could convince people to change their habits and more importantly maintain that change, I believe the benefits of small changes could be measured. Data would exist. Simply because we haven’t been able to design a study that captures all of this doesn’t mean the data doesn’t exist. It simply means the data doesn’t exist yet. The issue isn’t that small changes don’t work it is that we don’t maintain small change long enough to see the difference.
I could be proven hopelessly off base in the future. And if I am, so be it. That is the power of data. For now though I will continue to believe that small changes do make a difference and that we must maintain those small differences for the rest of our lives in order to be successful in weight loss. Are you ready for change? Small change? That takes us back to readiness for change which the New England Journal of Medicine article also disputed. I tend to believe their argument on this point. Who to believe, what to believe? I am so confused. I’m going to go for a small walk.