What Is Weight Loss Success?

Weight loss success can be defined in many ways. "If you are overweight or obese, just losing and keeping off 5% to 10% of your current weight has clear health benefits," says Hill.

Even not gaining weight every year can be considered success. Peeke recommends trying to sustain 75%-80% of your total weight loss. Once you get to the 50% point, it becomes a slippery slope, she says.

And how long does it take before maintenance gets easier? The National Weight Control Registry showed that participants seem to reach a point after about three years where they feel like they "have it," and will be able to keep the weight off forever, Hill adds.

"Clearly, the longer you keep the weight off, the more likely you are to keep it off permanently," says Hill.