Some researchers believe constant diet research is pointless, and the best way to prevent weight gain is a real lifestyle change.

"The amount of resources that have gone into studying 'what' to eat is incredible, and years of research indicate that it doesn't really matter, as long as overall calories are reduced," Bradley Appelhans of the Rush University Medical Center in Chicago, told LiveScience. "What does matter is 'how' to eat, as well as other things in lifestyle interventions, such as physical activity and supportive behaviors that help people stay on track [in the] long term."

The researchers expressed their findings the Journal of the American Medical Association (JAMA). In their editorial, they call attention to the fact that there has only been mild success with diet-focused weight loss, according to LiveScience. True lifestyle changes are needed in order to keep weight off.

"The 'diet' used within a lifestyle intervention can be low-fat, low-carb, etc. It doesn't matter," Sherry Pagoto of the University of Massachusetts Medical School in Worcester, Mass., a co-author of the editorial, said. "In fact, at least one study compared a low-fat lifestyle intervention with a low-carb lifestyle intervention, and it made no difference. The diet itself [is not] instrumental to the lifestyle interventions success; it is the behavioral piece that is key."

Recent studies that taught participants how to lose weight found their subjects had kept the pounds off years later.

Pagoto suggested a "three-pronged" approach to successful weight loss: "dietary counseling (how to control portions) reduce high-calorie foods and navigate restaurants), exercise counseling (how to set goals, target heart rate and exercise safely), and behavioral modification (how to self-monitor, problem solve, stay motivated and understand hunger)," according to LiveScience.

Pagoto believes lifestyle adherence is more important than diet itself. Regardless of their diet, Pagoto works to help her patients permanently incorporate healthier habits into their lifestyle.