Our lifestyle conditions what we will become in a few decades: six out of ten adults and one-third of children and adolescents will be overweight orobese by 2050. Estimates by a global group of experts emphasize the potential for future diseases: obesity is the trigger for cases of type 2 diabetes, cardiometabolic disorders, and even cancer.
The studies published today in the journal The Lancet reveal that in the last 30 years, the figures for excess weight in the population globally are alarming. Not only due to the number of adults but also because of the impact on new generations, with clear increases in the child population, including in Spain.
This new analysis estimates that the prevalence substantially increased between 1990 and 2021, doubling in both younger children and adolescents (from 8.8% to 18.1%) and older adolescents (from 9.9% to 20.3%), affecting 493 million young people in 2021. Similarly, obesity rates in children and adolescents tripled from 2% to almost 7%, and in 2021, 174 million young people were living with obesity.
"The unprecedented global epidemic of overweight and obesity is a profound tragedy and a monumental social failure," stated the lead author, Professor Emmanuela Gakidou, from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington (USA).
At the same time, research has a predictive section to focus on because there is still time to reverse the trends. Overweight during childhood and adolescence will stabilize between 2021 and 2050 as a greater number of people worldwide transition to obesity, with significant increases expected until 2030, continuing beyond 2031 to 2050.
How do obesity predictions affect our country?
If we focus on our country, obesity emerges as an emerging problem. In the 2050 predictions, we rank in the top 10 of high-income countries with an impact on new generations from ages 5 to 25. "We are not in the red light countries, but in the orange light, which is concerning," warns Marta Castell, the coordinator of the Working Group on Gastroenterology and Nutrition of the Spanish Association of Primary Care Pediatrics (AEPap).
She provides context because the traffic light only warns us: "The ALADINO study published at the end of 2024 shows a stabilization in terms of overweight and obesity rates in Spanish children compared to the previous 2019 study. But we are at very high values above what would be appropriate." Therefore, Castell urges the implementation of preventive actions: "We should be careful if we do not implement effective policies, because the trend is upward worldwide."
This study revealed that 36.1% of Spanish minors were overweight (20.2% overweight, 15.9% obese). The projections for our minors in 25 years according to The Lancet analysis imply growth of up to 47% in children aged 5 to 14; 48% in those aged 15 to 25; and 77% in those over 25 years old.
Castell points out that BMI, which the article is based on for metrics, is not everything in obesity. Recently, the same publication highlighted that neither the scale nor the BMI are definitive, and that obesity has been "wrongly defined" compared to what experts care about: "The clinical impact of the figures: if there are associated diseases. And this is very important when we talk about minors in stages of growth and change," emphasizes Castell.
It is also essential to find ways to halt the predictions from the analysis. "We must consider that obesity is multifactorial, not just one factor," emphasizes Cristobal Morales, an Endocrinology and Nutrition specialist at Vithas Sevilla Hospital.
Pediatrician Castell points to three pillars: "The nutrition of the youngest is conditioned by the accessibility of the shopping basket in their homes. Physical activity should be increased in schools, and there should be public policies that promote active and accessible leisure for all minors, with safe public spaces. All supported by responsible screen use."
Perhaps in our country, both children and adults have moved away from the pillars of the Mediterranean diet (also from the Atlantic, more common in the northern part of the country), as Castell points out. "Families no longer eat together or cook as our grandparents and great-grandparents did," acknowledges the pediatrician, attributing this to lifestyle rhythms and underlying socio-economic issues.
Globally, it is projected that more children aged 5 to 14 will live with obesity compared to those who are overweight by 2050 (16.5% versus 12.9%), while in women (5-24 years) and older men (15-24 years), overweight is expected to remain more common than obesity.
The analysis also highlights that recent generations are gaining weight faster than previous ones, and obesity is appearing earlier, increasing the risk of complications such as type 2 diabetes, hypertension, cardiovascular diseases, and multiple cancers at younger ages.
Therefore, Gakidou argues for action. "Governments and the public health community can use our country-specific estimates on the stage, timing, and speed of current and projected weight transitions to identify priority populations experiencing the greatest burdens of obesity requiring immediate intervention and treatment, and those that remain predominantly obese and should primarily be targeted with prevention strategies."
For example, in high-income countries, around 7% of men born in the 1960s lived with obesity at 25 years old, but this figure increased to around 16% for men born in the 1990s, and is projected to reach 25% for men born in 2015.