Inactivity, not overeating, is to blame for escalating obesity rates, according to a study released Monday by Stanford University.
Researchers at the Stanford University School of Medicine drew their conclusions after reviewing the results of a 22-year national healthy survey.
Scientists analyzed data from more than 17,000 participants from 1988 through 2010, and found that obesity rates rose in tandem with subjects' inactivity, but not with total caloric intake.
Participants recorded the frequency, duration and intensity of their exercise routines. The team defined “ideal” exercise as 150 minutes a week of moderate exercise or 75 minutes of vigorous exercise a week.
“What struck us the most was just how dramatic the change in leisure-time physical activity was,” said Uri Ladabaum, MD, associate professor of gastroenterology and lead author of the study.
“Although we cannot draw conclusions about cause and effect from our study, our findings support the notion that exercise and physical activity are important determinants of the trends in obesity.”
Fitness Experts: Diet Beats Exercise for Weight Loss
The Stanford study contradicts longstanding fitness wisdom that you can't out-exercise a bad diet, and that fit bodies are made in the kitchen — not the gym. "The Biggest Loser" trainer Bob Harper, a recognized obesity expert, insists diet trumps exercise for weight loss.
"It is all about your diet," said Harper. "I used to think a long time ago that you can beat everything you eat out of you, and it's just absolutely not the case."
Similarly, Paleo diet expert Mark Sisson maintains his rippling physique at age 60, thanks to the low-carb Paleo diet. Mark, a former Ironman triathlete, said he looks and feels better with less exercise since switching to the Paleo diet.
“I actually work out less,” Sisson told Palm Springs Life. “Thirty percent of your body composition is determined by how you eat.” The other factors are a combination of genetics, lifestyle, and exercise.
Paleo and Ketogenic Diets Spur Weight Loss With Little or No Exercise
To further underscore the importance of diet for weight loss, a woman made headlines last year after losing 80 pounds in 12 months on a high-fat, low-carb hybrid ketogenic-Paleo diet.
The 5-foot-4 Amanda, who declined to give her last name, slimmed down from 222 pounds to 134 pounds on a LCHF "ketogenic-Paleo" diet. Amanda (pictured above) said she lost the weight without any exercise.
Similarly, a New Zealand woman credited the LCHF ketogenic diet for her stunning 110-pound weight loss in seven months. Ariana Omipi slimmed down from 287 pounds to 177 pounds by eating lots of fat, moderate amounts of protein, and very few carbs.
Omipi revealed on YouTube she did not exercise at all in the first month and a half, and still experienced dramatic weight loss due to her low-carb ketogenic diet. When she started seeing huge results, Ariana began working out, and said she now exercises an hour a day.
Anecdotally, there are many marathon runners who are overweight, and gyms are routinely overrun with regulars who work out every day and never seem to lose a pound.
Whether diet beats exercise for weight loss or vice-versa, fitness experts agree exercise plays an important role in maintaining optimal health. Regular workouts set off a cascade of anti-aging metabolic changes that boost metabolism, burn body fat, and enhance immune health.