Eating fruits, vegetables linked to emotional well being

Psychology researchers Tamlin Conner and Bonnie White and nutrition researcher Caroline Horwath from New Zealand's University of Otago teamed up to investigate the relationship between day-to-day emotions and food consumption.

A total of 281 young adults (average age 20 years) with eating disorders were asked to complete an internet-based daily food diary for 21 consecutive days.

Participants had earlier completed a questionnaire giving details of their age, gender, ethnicity, weight and height, the British Journal of Health Psychology reports.

On each of the 21 days, participants logged into their diary and rated how they felt using nine positive and nine negative adjectives. They were also asked five questions about what they had eaten that day, according to an Otago statement.

Specifically, participants were asked to report the number of servings eaten of fruit (excluding fruit juice and dried fruit), vegetables (excluding juices), and several categories of unhealthy foods like biscuits/cookies, potato crisps, and cakes/muffins.

The results showed a strong day-to-day relationship between more positive mood and higher fruit and vegetable consumption, but not other foods.

"On days when people ate more fruits and vegetables, they reported feeling calmer, happier and more energetic than they normally did," says Conner.

To understand which comes first -- feeling positive or eating healthier foods, Conner and her team ran additional analyses and found that eating fruits and vegetables predicted improvements in positive mood the next day, suggesting that healthy foods may improve mood.

These findings held regardless of the BMI (height to weight) ratio of individuals.