Q: My mood hasn't been good for quite a while, and I'd like to start the new year on a brighter note. I'm wondering: Is it possible to change my diet so that I become a happier person? -Veronica W., Portland, Ore.

A:  Research certainly suggests it's possible. And the mood-boosting nutritional habit to adopt is one you probably never considered before.

We've all heard that we should eat our fruits and vegetables because they're "good for us." Studies have long shown that the risks of cancer and heart attacks are greatly reduced by a regular intake of these foods. Now science has found another reason to consume more fruits and vegetables: Eating enough of them boosts happiness and could make us happier people.

Satisfaction-Boosting Results from Eating More Fruits and Vegetables

In a study published last year in the American Journal of Public Health, researchers asked more than 12,000 people about how many fruits and vegetables they typically ate-once in 2007, and again in 2009. The subjects also rated their overall life satisfaction on a scale of 1 to 10 during both of those surveys.

Researchers looked at how each person's fruit and vegetable consumption and happiness changed over those two years, and found that with each extra serving of fruits and vegetables people ate, the happier-or more satisfied with life-they felt.

The researchers found that people who switched from eating almost no fruit and vegetables in their daily diets to eating eight portions of fruits and vegetables a day experienced an increase in life satisfaction and well-being equivalent to what an unemployed person feels after finding a job.

The relationship between higher levels of life satisfaction and increased fruit and vegetable intake persisted even after the researchers accounted for changes in the people's income or life circumstances.

While previous research has shown that eating more fruits and vegetables leads to improvements in people's physical health, these benefits typically occur over a long period of time, the researchers said. Individuals should take heart that there is a relatively quick psychological payoff from adopting healthier eating habits.

"People's motivation to eat healthy food is weakened by the fact physical health benefits accrue decades later, but well-being improvements from increased consumption of fruit and vegetables are closer to immediate," the researchers concluded.

Possible Reasons for the Benefit of Fruits and Vegetables

It's not clear why eating more fruit and vegetables is associated with greater levels of life satisfaction, the researchers said. One recent study links greater levels of carotenoids, found in some fruits and veggies such as carrots, to higher levels of optimism. It's also possible that eating more fruits and vegetables changes gut flora (the good and bad bacteria in the gut) in a way that improves brain chemistry.

Past research also suggests that there's a link between B vitamins-found in spinach, Brussels sprouts, and oranges-and production of serotonin, one of the chemicals in the brain that helps produce a happy mood.

This Australian study focused on the psychological effects of eating fruits and vegetables over two years. However, positive effects from fruits and vegetables on well-being may occur quite quickly. A previous study in 2013 found that a high level of fruit and vegetable consumption appears to result in greater emotional well-being the very next day.

Emphasize More Veggies than Fruits

The study was run in some Australian states in conjunction with the "Australian Go for 2&5 Campaign," which promotes the consumption of two portions of fruit and five portions of vegetables every day. This is a good general guideline for people. One serving equals half a cup of fresh, frozen, or unsweetened canned fruits and vegetables.

7 Ways to Boost Your Intake of Vegetables and Fruits

Try these tips for increasing your intake of vegetables, and to a lesser extent, fruits:

1. Include vegetables or fruit with breakfast

Add sautéed assorted vegetables, and have a side of fruit.

2. Substitute vegetables in place of pasta

Spaghetti squash and zucchini noodles are two great alternatives.

3. Have cut vegetables available as fast-food snacks

Cut them into sticks that you can easily grab from the fridge, and eat plain or with a dip.

4. Make celery sticks or apple slices with nut butter a go-to staple

This stabilizing snack is good between meals, and it can serve as an easy-to-make breakfast or lunch side dish.

5. Set out a fruit bowl in the kitchen

This encourages eating assorted varieties of fresh fruit instead of eating processed convenience foods such as crackers or chips.

6. Have some frozen vegetables and unsweetened fruits in the freezer

They can serve as essential backups when you can't make it to the store to get fresh produce.

7. Eat more than one type of vegetable with lunch and dinner

Emphasize two to three times more vegetables on your plate than protein, grains, or beans.

Written by Melissa Diane Smith for Better Nutrition and legally licensed through the Matcha publisher network. Please direct all licensing questions to [email protected].