Jan. 17 is often known as “Quitters Day” – a time when many abandon the New Year’s resolutions that they made on Jan. 1.

One of the most common resolutions that people make and then quit is to get in shape. But this is easier said than done. Obesity rates in the United States are on the rise, according to health officials.

Gyms and health clubs are usually packed after Jan. 1. And some New Jersey gym owners say that they have not noticed a major drop off in patrons. But some say that a temporary drop-off in attendance is inevitable.

So, why do so many fall short of achieving their goals? Psychiatrist Indra Cidambi says that the reason is simple – poor planning.

"They start making resolutions on the spur and they don’t think through those processes,” she says. “They don’t have a plan.”

Cidambi says that people who want to keep their resolutions should have a realistic goal in mind.

“Have steps to reach that [goal]. First week, ‘I'm going to lose two pounds or one pound,’ so when they do that, ‘I’m going to feel motivated. I've met my goal. I've achieved it. Now, I'm going to keep up with it,’” Cidambi says.

Experts say getting a personal trainer or taking a group fitness class may also help.