How to diet ... without getting cranky

It is possible to cut calories and lose weight without constantly feeling hungry and irritable, dietitians say. Here's how:

Eat "good" carbohydrates. Healthy carbohydrates boost levels of serotonin, a hormone produced in the brain that boosts mood. Get these nutrients from fruits, vegetables and whole grains.

Lose weight gradually. Suddenly slashing calories will make you very grouchy. Most people should aim to drop no more than a pound or two a week.

Go for variety. Your body and brain need foods from each of the major groups — proteins, carbohydrates and fats — to maintain proper chemical balances. Many dieters try to cut out fat; instead, focus on healthy sources such as salmon, nuts, avocado and olive or canola oil.

Stay away from junk. Sugary foods and drinks create a sudden burst of energy followed by a rapid drop in blood sugar levels. Low blood sugar, in turn, causes irritability, mood swings and problems with focus.

Eat often. Fasting also leads to low blood sugar levels. Stay on an even emotional keel by eating small portions every four to five hours; never let yourself get too hungry.

Get enough fiber ... This substance, found in plants and whole-grain cereals and breads, slows absorption of sugar from the bloodstream and can help prevent mood swings. Fiber-rich foods also keep you feeling full longer.

... and B-vitamins. Studies suggest low levels of folic acid and vitamin B12, in particular, may be linked to depression. Good choices include lentils, oatmeal, broccoli, sunflower seeds, shellfish, low-fat dairy products and fortified breakfast cereals.

Exercise. Like healthy foods, regular workouts boost the brain's production of serotonin. Getting out in the sunlight is even better.

Distributed by McClatchy-Tribune Information Services.