We all know the connection between exercise and weight loss — the more you work out, the more calories you burn, ergo, those 10 pounds you gained over the holidays will magically melt off as soon as you hit the gym again, right?
Well, actually, that might not be the case after all, and even thinking that there's a correlation between exercise and weight loss could be a big mistake.
Vox health writer Julia Belluz waded through more than 60 studies related to exercise and weight loss and spoke to nine exercise, nutrition and obesity experts for a feature in Vox's "Show Me the Evidence" series. And her research led her to the startling realization that, not only is exercise not helpful for losing weight, all the "fitness gurus, celebrities," even first lady Michelle Obama are "leading us astray in our fight against obesity" by reinforcing the message that exercise is good because it helps us lose weight.
That's not to say that exercise isn't good for us: as Belluz writes, "exercise is hugely important for overall health," it just doesn't seem to have much to do with weight loss, "how much and what you eat has a much bigger impact on your waistline."
Belluz referenced multiple studies that demonstrated that "physical activity alone" led to "only modest" weight loss, despite the many other health benefits of exercise. When it came to weight loss, Belluz found, nutrition is what really mattered.
"We've long thought of weight loss in simple 'calories in, calories out' terms," Belluz wrote, but this is "overly simple." Bodies aren't machines, they're complicated organisms, and in some ways, exercise can even have a counterintuitive effect on weight loss by making us extra hungry or by telling our body to "conserve energy."
"Every reliable expert I've ever spoken to on weight loss says the most important thing a person can do is to limit calories in a way they like and can sustain, and focus on eating more healthfully," Belluz wrote.
Of course, losing weight doesn't necessarily equal being healthy: A 2012 study on "fitness and fatness" found that some people who are overweight or obese are "metabolically healthy," and aren't at any greater risk for chronic disease like "cardiovascular problems and cancer" that can sometimes be linked to obesity.
It's clear that weight loss isn't always a goal for people who want to be healthier, and exercise has undeniable benefits to your body, something Belluz's investigation only reaffirms. So just because it may not lead to weight loss doesn't mean it's time to cancel your gym membership just yet.