Eating more fruit and vegetables may make young people
calmer, happier and more energetic in their daily life, new
research from the University of Otago suggests.
Researchers from the department of human nutrition,
investigated the relationship between day-to-day emotions and
The study is published in the British Journal of Health
A total of 281 young adults, aged about 20, completed an
internet-based daily food diary for 21 days. Before 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.
The participants 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 biscuits/cookies, potato chips and
cakes and muffins.
Researcher Caroline Horwath said 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
Dr 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
might improve mood.
These findings held regardless of the body mass index of the
"After further analysis we demonstrated that young people
would need to consume approximately seven to eight 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."
Dr Conner said to get the amount needed to increase
positivity, people should make half their plate at each meal
vegetables and snack on whole fruit, like apples, during the
While this research showed a promising connection between
healthy foods and healthy moods, further research was
necessary and the researchers recommend the development of
random control trials evaluating the influence of high fruit
and vegetable intake on mood and wellbeing.