Which Diet and Exercise Plans Work Best?

August 29, 2011

Supervised exercise plans, when combined with healthy eating, lead to more weight loss and help keep the weight off longer, according to a recent study

Supervised exercise plans, when combined with healthy eating, lead to more weight loss and help keep the weight off longer, according to a recent study from Texas A&M University and others. 

The study looked at a group of sedentary obese women over a 10-week period and found that they had better results when adhering to a supervised diet and exercise plan (SDE) than those that were simply encouraged to increase their physical activity while following a meal replacement-based diet (MRP). Lead investigator Dr. R. B. Kreider of Texas A&M University says that this is one of the few comparative effectiveness trials that have compared different exercise, diet, and behavioral approaches. 

"We found that both diet approaches worked. However, participating in a more structured program worked better," says Kreider. "It's important to realize that different diet approaches may work better in some individuals compared to others, and part of the art involved in promoting weight loss is identifying which approach works best in a given individual."

While both groups lost weight and fat mass, the SDE group lost significantly more weight, and their BMI decreased to a greater degree. The SDE group reported that they engaged in a greater number of moderate and vigorous physical activity sessions than the MRP group too. And as a result, they experienced a significantly greater increase in peak aerobic capacity.

Additionally, the SDE group reported more energy, although there were no significant interactions between groups in appetite, hunger, fullness, diet satisfaction or diet quality. There were also no significant differences observed in baseline age, height, weight, or percent body fat. Protein intake was higher in the SDE group, and generally, physical function and vitality levels increased to a greater degree in the SDE group.

With an estimated 1.2 billion people overweight and at least 300 million people considered obese, obesity has become a worldwide epidemic associated with an increased risk of diseases and health conditions. One of the greatest challenges health professionals face is trying to find weight loss plans that consumers can adhere to and maintain over time. 

Without being able to incorporate diet and exercise plans into one's lifestyle, the weight loss portion of the program is almost always short-lived. That's why interest in identifying programs that work and can be merged with lifestyle behaviors has been driving interventions of late.

The ready-to-eat meal (cereals, bars, etc.) is one recommended approach to promote weight loss and reduce daily energy intake, and studies have shown that this tactic works. In this study, ready-to-eat cereals and bars from the Special K Challenge program were used in the MRP group to promote weight loss – and it worked well. Using this approach, energy was reduced by approximately 300 to 450 kcal/day throughout the study. These participants were encouraged to exercise, and they did so in moderation.

But as compared to the MRP group, participants in the SDE group engaged in more than an hour per week more exercise (through the Curves diet program), the primary reason why their weight loss results were so much better overall. One important difference here is that this type of SDE program, says Kreider, provides social support that allows overweight women an opportunity to exercise and experience their weight loss journey together. There is more accountability, and there is positive peer motivation to work out and follow the SDE. 

"Comparatively, without the social support network and expectations to exercise, there is less motivation and accountability. I also think the Curves program is particularly effective in this population because weight loss can be achieved without loss of muscle mass or resting energy expenditure (metabolism). Women see results quickly in fitness, strength, and weight loss, which is also a motivating factor," says Kreider.

These findings suggest that a supervised exercise program, combined with adherence to a meal plan, is a more effective approach to weight loss and maintaining weight loss than a diet that provides ready-to-eat meals and educates participants about increasing their physical activity.

"Everyone knows they need to exercise but it's sometimes better to work out with friends or have a personal trainer to improve accountability," says Kreider. "Meal replacement programs can help but if you really want to see meaningful results, commit to a structured exercise and weight loss program."