A Mediterranean diet can almost halve your risk of becoming obese, a landmark study has found.
The diet rich in vegetables, nuts, grains and olive oil slashes the likelihood of you getting too fat by 43%.
Even without doing any more exercise, people can dramatically cut their risk of getting chubby simply by adopting the Mediterranean diet, the research found.
One in four adults in the UK is obese.
Now research presented at the world’s biggest obesity conference found that adopting the diet can provide “substantial protection” against the threat of obesity.
A typical Mediterranean diet includes high intakes of plant-based proteins such as nuts, lentils and beans, whole grains, and healthy monounsaturated fats such as olive oil.
Meat is kept to a minimum.
Researcher Julen Sanz, who led the research involving 16,000 people over more than a decade, said: “Our study suggests that plant-based diets are associated with substantially lower risk of developing obesity.
“This supports current recommendations to shift to diets rich in plant foods, with lower intake of animal foods.”
Experts have long known that a Mediterranean diet can reduce your risk of cardiovascular disease and Type 2 diabetes.
But until now little was known about its role on the risk of developing obesity.
Now a major new study presented at the European Congress on Obesity, in Porto, Portugal, has found that eating a diet rich in fruit and vegetables could cut obesity risk.
Consultant cardiologist Dr Aseem Malhotra, an adviser to the National Obesity Forum, said: “This study provides further strong evidence that adopting a Mediterranean style diet significantly reduces the chances of obesity.
“The UK government need to urgently adopt a health policy that makes a healthy diet easily accessible and affordable for all.
“Not only will this reverse the obesity epidemic but it will quickly reduce the burden of all associated lifestyle diseases that have brought our NHS to the brink of collapse.”
Pro-vegetarian diets with a higher level of plant-based foods compared to animal-based foods can provide “substantial protection” against obesity,the new research found.
The observational study found that people who ate a high pro-vegetarian diet - rich in food coming from plant sources like vegetables, fruit, and grains - cut their risk of developing obesity by almost half compared to those who were least pro-vegetarian - with a dietary pattern rich in animal food like meat, and animal fats.
The study was carried out by Spain’s University of Navarra.
Researchers examined the association between varying degrees of pro-vegetarian plant-based diet and the incidence of obesity in 16,000 healthy, non-obese adults in Spain.
Participants completed food questionnaires, and researchers used a pro-vegetarian diet index (PVI) to score each participant on the types of food they ate.
Points were given for eating seven plant food groups - vegetables, fruits, grains, nuts, olive oil, legumes (such as peas, beans, and lentils) and potatoes.
Points were subtracted for five animal groups - animal fats, dairy, eggs, fish and other seafood, and meat.
Based on their scores, participants were put into five groups from the 20% with the least pro-vegetarian diet to the 20% with the most, and followed for an average of 10 years.
During the study, 584 participants became obese.
The researchers found that participants who closely followed a pro-vegetarian diet were less likely to become obese.
Modelling showed that compared to the least-vegetarian participants, the most vegetarian had a 43% reduced risk of developing obesity. When the researchers removed potatoes from the healthy group of foods, the impact of a Mediterranean diet in reducing obesity risk was even higher.
Commenting on the research, Gaynor Bussell, a dietitian and member of the British Dietetic Association, said: “We have known for a while that a healthy plant based diet is associated with less obesity and this new evidence confirms this.
“I would also add that although scored negatively, foods such as fish, some meat and dairy are not associated with obesity but it is about the overall balance of the diet.
“The Mediterranean diet with its reliance on fruit, veg, nuts, beans and little meat is probably an ideal mix and is also associated with lower obesity rates.”
Dietitian Tanya Haffner, founder and director of Nutrilicious and member of the British Dietetic Association, added: “This large seemingly well conducted, well controlled observational study on plant-based diets versus animal based diets is unsurprising but a very interesting and helpful addition to our accumulating knowledge of plant-based versus animal based nutrition and its impact on our health.
“The more plant-based our diets are the better our health outcomes will be, particularly in relation to cancer, heart disease and obesity.”
Newcastle University clinical diabetes research expert Professor Mike Trenell, whose app Changing Health is being prescribed to help NHS patients with Type 2 Diabetes improve lifestyle habits including diet, said: “The evidence that eating a so-called Mediterranean based diet leads to better health and lowered risk of developing chronic illness is clear.
“The urgent need now is for policy makers to work with scientists and public health leaders to implement programmes that will support people to change their behaviour - the way they eat and amount they move too - at scale.”