(Undated) -- In just a few weeks, people will start making New Year's resolutions. Registered Dietitian Laura Jeffers says if you want to go on a diet, start making small changes to what you eat now. Stay away from eliminating foods from your diet right now. Jeffers says all you need to do is focus on portion control. If you're having a hard time cutting calories, one simple way is to replace calorie-filled drinks with water.