OTAGO, New Zealand—Eating fruit and vegetables may promote emotional well-being among healthy young adults by making them calmer, happier and more energetic during their daily life, according to a new study published in the British Journal of Health Psychology.
Researchers at the University of Otago’s department of psychology and the department of human conducted a study to investigate the relationship between day-to-day emotions and food consumption. For the study, 281 young adults with a mean age of 20 years completed an internet-based daily food diary for 21 consecutive days. Prior to this, participants completed a questionnaire giving details of their age, gender, ethnicity, weight and height. Those with a history of an eating disorder were excluded.
On each of the 21 days participants logged into their diary each evening 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. Specifically, they 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 cookies, potato chips and muffins.
Results showed a strong day-to-day relationship between more positive mood and higher fruit and vegetable consumption, but not other foods. Additional analyses found eating fruits and vegetables predicted improvements in positive mood the next day, suggesting healthy foods may improve mood. The findings held regardless of the BMI of individuals.
"After further analysis we demonstrated that young people would need to consume approximately 7-8 total servings of fruits and vegetables per day to notice a meaningful positive change. One serving of fruit or vegetables is approximately the size that could fit in your palm, or half a cup. My co-author Bonnie White suggests that this can be done by making half your plate at each meal vegetables and snacking on whole fruit like apples," the researchers said.
While the research shows a promising connection between healthy foods and healthy moods, the researchers recommend developing randomized control trials evaluating the influence of high fruit and vegetable intake on mood and well-being.