Bore yourself thin, doctors say, in a blow to diet gurus
But cardiac specialists say that could lead to poor eating patterns, an increase in junk food consumption and consequent weight gain and poor health.
Their study found many health experts and even public bodies recommend a wide variety of foods as a way to get all the necessary nutrients into your diet.
The idea is meant to encourage those who do not eat healthily to pack in more fruit, vegetables and fibre.
But in practice, those who ate the widest variety of foods are just as likely to tuck into more unhealthy dishes.
Lead researcher Marcia de Oliveira Otto said: “Eating a more diverse diet might be associated with eating a greater variety of both healthy and unhealthy foods.
“Combined, such an eating pattern may lead to increased food consumption and obesity.
“There is no evidence that greater overall dietary diversity promotes healthy weight or optimal eating.”
The American Heart Association conducted an overview of a number of studies into eating habits from the past 18 years.
Its report in AHA journal Circulation says there is some evidence a wider variety of food in a meal may delay the feeling of fullness, so diners eat more.
It advises eating more fruit, vegetables, beans, grains, nuts, poultry and fish and cutting down on red meat, sweets and sugary drinks.
And, though it may be boring, sticking to the same kinds of foods is probably best.
Dr Otto said: “Selecting a range of healthy foods, which fits one’s budget or taste, and sticking with them, is potentially better at helping maintain a healthy weight than choosing a greater range of foods that may include less healthy items such as doughnuts, fries and cheeseburgers, even in moderation.”