The science of joy

• Eat good food for a good mood
• Take control of your time
• Think negative
• Settle down before a shot

You know that eating well is great for your body, but it turns out it's great for your frame of mind as well. A study from the National Cancer Institute in Maryland found that people who switched to a healthy eating plan (less fat, more fibre and at least five to eight servings of fruit and veggies a day) were happier with their quality of life than those who continued their regular diet. The authors of the study theorize that the healthy eaters gained a feeling of satisfaction from doing something good for their body and their health.

Grin and try it Plan good-for-you meals with our Meal plans.

Busy? Of course you are. But feeling as though you have control of your time goes a long way, according to the Women's Health Australia project, a 20-year survey of 41,000 women. Those who expressed happiness about their work hours (regardless of how many hours they worked) had better mental and physical health.

Grin and try it Do some research on the hours typically worked in your industry (including so-called social events), analyse your needs and then negotiate more job flexibility, such as asking for more vacation time at less pay, telecommuting once a week or taking some unpaid leave.

It's not as crazy as it sounds, according to Julie Norem, a psychology professor at Wellesley College in Massachusetts and author of The Positive Power of Negative Thinking (Basic). "When defensive essimists think of everything that can go wrong, it lowers expectations and reduces anxiety and stress," she says. Pessimists who plan ways to counteract the things they think will go wrong might be better off than optimists who ignore potential risks.

Grin and try it Say you're anxious about a presentation at work. Instead of denying that you're stressed, channel your anxiety in a positive way and do a run-through with a friend or colleague to make sure that you're prepared.

Stressed out? Better reschedule that flu shot. Studies have shown that some vaccinations (including those for hepatitis B and influenza) work less effectively when you're under pressure. It appears that when stress overloads, the antibody and T-cell response of your immune system poops out too.

Grin and try it Try to time vaccinations for days when you're not rushed. Freaked out by needles? Tell the nurse so she can help you deal with it.