If you had just one piece of health advice for someone in their 20s, what would it be?

That’s the question posed to a number of experts in nutrition, obesity, cardiology and other health disciplines. While most 20-year-olds don’t worry much about their health, studies show the health decisions we make during our third decade of life have a significant effect on how well we age.

Staying healthy in your 20s is strongly associated with a lower risk for heart disease in middle age, according to research from Northwestern University. That study showed that most people who adopted five healthy habits in their 20s — a lean body mass index, moderate alcohol consumption, no smoking, a healthy diet and regular physical activity — stayed healthy well into middle age.

And a disproportionate amount of the weight we gain in life is accumulated in our 20s, according to data from the Centers for Disease Control and Prevention. The average woman in the United States weighs about 150 when she’s 19, but by the time she’s 29, she weighs 162 pounds. An average 19-year-old man weighs 175 pounds but by the time he hits 29, he weighs in at 184 pounds.

Young people often spend long hours at work, making it tough to exercise and eat well. They face job pressure, romantic challenges, money problems and family stress. Who has time to think about health?

To make it easier, a panel of experts was asked for just one simple piece of health advice. We skipped the obvious choices like no smoking or illegal drug use — you know that already. Instead we asked them for simple strategies to help a 20-something get on the path to better health. Here’s what they had to say.

Weigh yourself often

Buy a bathroom scale or use the gym’s and weigh yourself regularly. Nothing is more harmful to long-term health than carrying excess pounds, and weight tends to creep up starting in the 20s. It is pretty easy for most people to get rid of 3 to 5 pounds and much harder to get rid of 20. Keep an eye on your weight to catch it quickly.

– Susan Roberts, director of the Energy Metabolism Laboratory at Tufts University

Learn to cook

Learning to cook will save you money and help you to eat healthfully. Your focus should be on tasty ways to add variety to your diet and to boost intake of veggies, fruits and other nutrient-rich ingredients. As you experiment with herbs and spices and new cooking techniques, you will find that you can cut down on the unhealthful fats, sugar and salt, as well as the excess calories found in many prepared convenience foods.

– Barbara Rolls, professor and Guthrie Chair of Nutritional Sciences at Penn State

Cut back on sugar

I suggest that young people try to avoid excessive simple sugar by eliminating the most common sources of consumption: 1) sugared soft drinks 2) breakfast cereals with added sugar and 3) adding table sugar to foods. Excessive sugar intake has been linked to obesity and diabetes. Sugar represents “empty calories” with none of the important nutrients needed in a balanced diet. Conversely, the traditional dietary villains, fat, particularly saturated fat and salt, have undergone re-examination by many thoughtful nutrition experts. In both cases, the available scientific evidence does not clearly show a link to heart disease.

– Steven Nissen, chairman of cardiovascular medicine at the Cleveland Clinic

Live an active life

While many people can’t find time to schedule exercise, that doesn’t mean you can’t find time to be active. Build physical activity into your daily life. Find a way to get 20 or 30 minutes of activity each day, including bike riding or brisk walking to work.

– Walter Willett, nutrition department chairman, Harvard School for Public Health

Practice portion control

When eating out, let your hand be your guide. A serving of protein like chicken or fish should be the size of your palm. A serving of starch, preferably a whole grain such as brown rice or quinoa, should be the size of your fist. Limit high-fat condiments like salad dressing to a few tablespoons — a tablespoon is about the size of your thumb tip.

– Lisa Young, adjunct professor of nutrition at New York University

Eat your veggies

Nutrition science is complicated and debated endlessly, but the basics are well established: Eat plenty of plant foods, go easy on junk foods, stay active. The trick is to enjoy your meals, but not to eat too much or too often.

– Marion Nestle, professor of nutrition at New York University

Adopt a post-party exercise routine

If you engage in a lot of drinking and snacking, ensure that you exercise a lot to offset all those extra calories. We found in a study that on Friday to Sunday, young adults consumed about 115 calories a day more, mainly from fat and alcohol.

– Barry Popkin, professor of global nutrition at the University of North Carolina at Chapel Hill

Find a job you love

People who are less happy in their jobs are more likely to report depression, stress and sleep problems and have lower overall mental health scores. If I can give just one piece of health advice for a 20-year-old person, I would suggest he or she find a job they feel passionate about. That in turn will make them more engaged in life and healthier behaviors, which will have long-term benefits for their well-being.

– Hui Zheng, associate sociology professor, population health, Ohio State University