Keeping your New Year's resolution of losing weight

(NBC) - It's one of the top resolutions many of us make every New Year -- lose some weight.  Now one doctor says you can do it -- and keep it off if you follow his simple advice.

Dr. Douglas Cluff, the man behind the SvelteLife Weight Loss Program, said losing weight begins at the grocery store.  It's all in how you fill your cart.

"If 80 percent of what you eat is healthy," Cluff explained, "You can totally have fun with the other 20 percent."

The family doctor from Texas teaches patients and clients how to read food labels and choose their food wisely.

"So if you go to frosted mini-wheats, you got the frosted part," Cluff said, "But even look up here, you've got six grams of fiber."

The entire weight loss system is also online in a program called "SvelteLife".

The simple program emphasizes healthy eating, realistic goals, stress management and regular exercise with routines he developed.  Cluff said you get an amazing workout of most major muscle groups in about 10 minutes.

Ashley Baxter struggled with her weight for years -- then lost 67 pounds over three years on the SvelteLife program.

"It's actually very easy," explained Baxter, "But the hardest part is the fact that it takes a long time. You have to slowly change your life so that you can keep it that way and then your weight will come off slowly and surely and you'll become more healthy."

Cluff said the key is watching what you eat and how much.

"What people eat is nowhere near as important as how much of it they eat," Cluff said. "And so in moderation, that 80-20 rule is crucial."