Does Obesity Affect Life Expectancy?
Yes, obesity can significantly affect life expectancy. Studies have shown that obesity can lead to various health complications, which can shorten a person's lifespan. It's important to maintain a healthy weight to increase life expectancy. Keep reading to find out.
What Is Obesity?
Obesity is a chronic disease characterized by the abnormal or excessive accumulation of fat or adipose tissue [1, 2]. Most of the time, it impairs the health of the individual. It is a complex disorder of appetite regulation and energy metabolism when many different factors come into play [3].
Obesity is more than just excessive fat. In fact, one is often genetically predisposed to obesity. The metabolic, hormonal, and behavioral aspects result in significant morbidity, reduced quality of life, discrimination, and early mortality [4]. It is associated with multiple medical conditions, mental health problems and can cause serious complications of chronic conditions [2].
Obesity is universally defined as an excess of adipose tissue resulting in a body mass index (BMI) greater than 30.0 kg/m^2 [5, 6]. The condition that comes before obesity is being overweight and is defined as BMI from 25 to 30 kg/m^2.The World Health Organization (WHO) defines obesity as abnormal or excessive fat accumulation that presents a health risk [7].
Obesity is a significant public health epidemic which has progressively worsened over the past 50 years [1, 2]. It is the second most common cause of preventable death after smoking [1, 2]. It stems from the imbalance of energy intake and expenditure.
Obesity increases your risk of diabetes, heart disease, stroke, arthritis, and some cancers [8]. A 5% to 10% weight loss can significantly improve the health, quality of life, and economic burden of an individual and a country as a whole [1, 2, 8].
Does Obesity Influence Life Expectancy?
Obesity is a significant health concern that has been linked to a reduction in life expectancy. Research has shown that obesity can decrease life expectancy by 5.8 years in men and 7.1 years in women after the age of 40 [9]. This reduction in life expectancy could be due to obesity accelerating aging at multiple levels, including compromising genomic integrity, or modifying the DNA methylation pattern. The latter has been associated with epigenetic ageing (a process by which biological aging is assessed and influenced through changes in DNA methylation and other epigenetic mechanisms, reflecting the functional decline and health risks associated with age)[9].
However, the impact of obesity on life expectancy can vary depending on age. Obesity has been found to have little effect on life expectancy in adults aged 70 years and older [10]. But, on the other hand, obesity in this age group is more likely to increase the probability of developing some kind of disability. That means that obese older adults may live more years, but a higher proportion of their remaining years might be with a lower quality of life[10].
When it comes to life expectancy, the length of obesity plays a role. Studies have shown that the risk of mortality increases with the number of years lived with obesity [11]. For every additional 2 years of obesity, the risk of cardiovascular disease, cancer, and other causes of mortality increases [11].
In conclusion, obesity does reduce life expectancy and the quality of life, although not always directly. It can also increase the risk of disability and chronic diseases. Therefore, addressing obesity is crucial for improving both life expectancy and the quality of life.
How Long Do Obese People Live?
The life expectancy of obese individuals can vary based on several factors, including age, gender, and the severity of obesity.
A study done on middle-aged women and men provides an argument for obesity lowering life expectancy. The population life is decreased by a factor of 0.8 for both sexes.[12]
Interestingly, the same study found that the highest life expectancy at age 55 was found in overweight individuals (BMI 25-29.9), slightly higher than a BMI 23-24.9 in both sexes [12].
As was mentioned before, the impact of obesity on life expectancy seems to lessen with age. For instance, a study found that obesity had little effect on life expectancy in adults aged 70 years and older [10]. On the contrary, a different study shows that young people who were obese during their childhood have a higher mortality rate compared to a population-based comparison group[13].
In contrast, a study on older U.S. adults found that those with obesity had an active life expectancy (ALE) at age 65 of 11.1 years, which was 1.2 years less than that for normal weight and overweight persons [14].
In conclusion, while obesity can potentially reduce life expectancy, the impact varies based on factors such as age, gender, and the duration of obesity.