1 in 5 people will be obese by 2025, study says

By Joshua Berlinger, CNN

Updated 1021 GMT (1821 HKT) April 1, 2016

The Western diet is spreading across the world. It's characterized by a high intake of red meat, refined sugars and saturated fat -- but little fiber.
Photos: Why a Western diet could be bad for you
The Western diet is spreading across the world. It's characterized by a high intake of red meat, refined sugars and saturated fat -- but little fiber.
Hide Caption
1 of 9
A common feature of Western diets is processed fast food. Here's a pepperoni pizza high in fat and carbohydrates and topped with cured, processed meat.
Photos: Why a Western diet could be bad for you
A common feature of Western diets is processed fast food. Here's a pepperoni pizza high in fat and carbohydrates and topped with cured, processed meat.
Hide Caption
2 of 9
Candy bars have been highlighted as a key example of processed foods. Ingredients such as fructose and palmitic acid may initiate a low-level immune response in the body, distracting the immune system from other infections.
Photos: Why a Western diet could be bad for you
Candy bars have been highlighted as a key example of processed foods. Ingredients such as fructose and palmitic acid may initiate a low-level immune response in the body, distracting the immune system from other infections.
Hide Caption
3 of 9
Some studies have linked eating too much red meat with a <a href="http://edition.cnn.com/2012/03/12/health/red-meat-shorten-lifespan/">shortened life span</a>.<br />
Photos: Why a Western diet could be bad for you
Some studies have linked eating too much red meat with a shortened life span.
Hide Caption
4 of 9
Sugary drinks are the epitome of the fast-food diet. Their high sugar content increases the likelihood of obesity, diabetes and other health conditions.
Photos: Why a Western diet could be bad for you
Sugary drinks are the epitome of the fast-food diet. Their high sugar content increases the likelihood of obesity, diabetes and other health conditions.
Hide Caption
5 of 9
The Mediterranean diet is renowned for its health benefits. It contains low levels of red meat, sugar and saturated fats and is high in fish and unsaturated fats such as olive oil, fruits, vegetables and legumes.
Photos: Why a Western diet could be bad for you
The Mediterranean diet is renowned for its health benefits. It contains low levels of red meat, sugar and saturated fats and is high in fish and unsaturated fats such as olive oil, fruits, vegetables and legumes.
Hide Caption
6 of 9
Diets with little fruit and vegetables can be low in vitamins, minerals and fiber crucial to growth and health.
Photos: Why a Western diet could be bad for you
Diets with little fruit and vegetables can be low in vitamins, minerals and fiber crucial to growth and health.
Hide Caption
7 of 9
The Japanese diet is also known for its healthy components -- high in soy protein and vegetables.
Photos: Why a Western diet could be bad for you
The Japanese diet is also known for its healthy components -- high in soy protein and vegetables.
Hide Caption
8 of 9
Diets on the southern Japanese Okinawa Islands contain large amounts of fish, whole grains, soy protein and vegetables.
Photos: Why a Western diet could be bad for you
Diets on the southern Japanese Okinawa Islands contain large amounts of fish, whole grains, soy protein and vegetables.
Hide Caption
9 of 9
Man eating hamburger close-uppepperoni pizzachocolate candy barSteaks on the grillCup of sodamediterranean dietBare fresh produceRamen hokkaido misosushi japan

(CNN)The obesity epidemic has gone global, and it may be worse than most thought.

A new study in The Lancet says that if current trends continue, 18% of men and 21% of women will be obese by 2025.