After analyzing the 21-day food diaries of 281 young adults, researchers in New Zealand determined that the happier people were the ones who ate more fruits and vegetables. Each day the subjects were asked to report their negative and positive affect, as well as their consumption of five specific foods including fruit, vegetables and several categories of unhealthy foods: biscuits/cookies, potato crisps, and cakes/muffins. Fruit juice, vegetable juice and dried fruit were to be excluded in the fruit and vegetable categories. On days when participants ate more fruits and vegetables, they reported feeling calmer, happier and more energetic than they normally did. Eating more fruits and vegetables actually predicted improvements in positive mood the following day, rather than positive moods predicting healthful eating. These results were independent of participants’ BMI. Further analysis determined 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.
Reference: White et al. Many apples a day keep the blues away – Daily experiences of negative and positive affect and food consumption in young adults. Brit J Health Psych. 2013.