Eating healthy means eating happy, and now a new study shows just how many fruits and veggies you need to eat each day to achieve optimal mental well-being.

The magic number? Seven 80-gram servings of fruits and vegetables every day, researchers from the University of Warwick and Dartmouth College found.

"The statistical power of fruit and vegetables was a surprise. Diet has traditionally been ignored by well-being researchers," study researcher Sarah Stewart-Brown, a professor of public health at the University of Warwick, said in a statement.

Researchers pointed out that five servings a day of fruits and vegetables are already recommended by many health departments for physical health.

The study, which will be published in the journal Social Indicators Research, is based on the diets and well-being scores of 80,000 people in Great Britain who participated in the Welsh Health Survey, Scottish Health Survey and Health Survey of England between 2007 and 2010.

The researchers examined the study participants' mental well-being by looking at factors including mental disorders, feeling "low," happiness, nervousness, and how well they reported their own health as being.

They found an association between peak well-being and consuming about seven portions of fruits and vegetables every day.
"Our findings are consistent with the need for high levels of fruit-and-vegetable consumption for mental health and not merely for physical health," they wrote in the study.