The Surprising Truth About Weight Loss and Longevity 

Do you struggle with keeping weight off as you enter your midlife years? If so, you're not alone. Many individuals, as they age, experience changes in their metabolism that make it harder to stay trim.  

However, some research suggests these pesky extra pounds may actually benefit long-term health.   

While weight loss is often touted as the solution to a healthier life, multiple studies have found that being too thin or losing weight after a certain age may negatively impact longevity. 

Read on to learn why striving for a certain body size may not necessarily be the best path to a long and healthy life, and what you should focus on instead.  

What Is a Healthy Weight?  

Body Mass Index (BMI) is the standard measure for assessing body size. This calculation considers your weight in relation to your height to determine if you are at risk for weight-related health conditions.  

It has its limitations. For example, it doesn’t consider lean muscle mass, which typically weighs more than fat. Therefore, very lean individuals may fall within an unhealthy BMI category despite being fit.  

BMI also doesn’t reflect genetic and lifestyle factors associated with health status. Someone with a higher BMI who eats a balanced diet and is regularly physically active is unquestionably healthier than a naturally thin person with a poor diet and sedentary lifestyle.  

Still, doctors and researchers rely on BMI as a screening tool for health risks, as follows:  

• A BMI less than 18.5 is considered underweight. 
• A BMI of 18.5 to less than 25 is considered healthy. 
• A BMI of 25 to less than 30 is considered overweight. A BMI of 30 or more is considered obese.  

The Link Between Body Weight And Mortality  

Being overweight or obese has consistently been linked to numerous health risks that affect longevity and quality of life. However, this link seems to weaken with age.  

In fact, carrying a few extra pounds after middle age may actually protect your health.  

A large study analyzed data from the Centers for Disease Control and Prevention's (CDC) National Health and Nutrition Examination Survey (NHANES). The findings revealed that individuals classified as overweight (but not obese) had slightly lower mortality rates than those falling within normal weight ranges.  

On the other hand, underweight individuals had a significantly higher risk of premature death. Moreover, although this study identified a correlation between obesity and increased health risks, this association was weaker in older age groups.  

Another analysis of 51 different studies published in the Journal of Epidemiology and Public Health had similar findings. Researchers found that underweight individuals had nearly double the risk of premature death compared to normal-weight study subjects.  

Carrying a few extra pounds has also been associated with a lower risk of hip fracture, which significantly impacts mobility and quality of life in later years.  

Losing Too Much Weight Can Decrease Life Span  

Not only can a little extra weight benefit older adults, but weight loss after middle age may have adverse health effects.  

The Framingham Study, a long-term study designed to identify characteristics contributing to heart disease, found that weight loss throughout the 24-year study period was associated with increased mortality.  

Losing weight results in fat loss as well as the loss of muscle mass. These effects can worsen the skeletal muscle losses that accompany the normal aging process. Maintaining muscle mass and strength is a crucial driver of mental and physical health throughout the lifespan.  

A few caveats—this study found that weight gain over time increased health risks. Therefore, while weight loss may not always be necessary or beneficial, adopting healthy habits to maintain your weight can improve your long-term wellness.  

Furthermore, while a few extra pounds may not be a major concern, a BMI over 35 is associated with poor long-term health. If you fall in this category, a modest amount of slow and steady weight loss will help improve your functional and physical health.  

Consider aiming for a gradual rate of weight loss of about one pound per week until you've achieved a 5 to 10% reduction in your body weight. This approach can help you reap the benefits of reducing weight while minimizing potential harmful effects. 

Lifestyle Factors Are Better Predictors Of Long-Term Health Than Weight   

Altogether, this research indicates that there are better strategies than focusing on body weight alone to ensure you enjoy a long and fulfilling life.  

While it's tempting to focus on the number on the scale, it's important to remember that lifestyle factors play a much greater role in promoting long-term health. 

In fact, regardless of weight, being physically active for at least 150 minutes each week can help: 

• Raise good (HDL) cholesterol levels, reducing the risk of cardiovascular disease and stroke.  
• Maintain physical function, strength, and flexibility.   
• Boost mood and combat age-related cognitive decline.  

Including lean proteins in your diet – like seafood, poultry, nuts, and seeds – will also help preserve muscle mass and strength, reducing the risk for osteoporosis and disabilities. Experts recommend adults consume 1 to 1.2 grams of protein per kilogram of body weight, which is about 70 to 90 grams of protein for a 180-pound person. 

Research also consistently shows that eating five servings of fruits and vegetables daily can add years to your life. Consuming at least this many servings of produce every day lowers mortality rates associated with cardiovascular disease, cognitive decline, respiratory illness, and cancer for people at both ends of the BMI range. 

The Bottom Line   

It’s understandable to feel concerned about weight gain as we age, but it's important to remember that the number on the scale is just one piece of the puzzle when it comes to promoting long-term health and longevity.  

While weight loss may be beneficial in some cases, it's not always the best approach, and may even be harmful.   

So give yourself a break from obsessing over the scale, and focus on incorporating healthy habits into your daily routine. By doing so, you can prioritize your health and well-being in a way that truly makes a difference. 

References: 

Centers for Disease Control and Prevention. (n.d.). Assessing your weight. Retrieved April 17, 2023, from https://www.cdc.gov/healthyweight/assessing/bmi/index.html 

Flegal KM, Graubard BI, Williamson DF, Gail MH. Excess deaths associated with underweight, overweight, and obesity. JAMA. 2005;293(15):1861-1867. 

Cao S, Moineddin R, Urquia ML, Razak F, Ray JG. J-shapedness: an often missed, often miscalculated relation: the example of weight and mortality. J Epidemiol Community Health. 2014;68(7):683-690.  

Tang X, Liu G, Kang J, et al. Obesity and risk of hip fracture in adults: a meta-analysis of prospective cohort studies. PLoS One. 2013;8(4):e55077. Published 2013 Apr 12. 

Xu H, Cupples LA, Stokes A, Liu CT. Association of Obesity With Mortality Over 24 Years of Weight History: Findings From the Framingham Heart Study [published correction appears in JAMA Netw Open. 2018 Dec 7;1(8):e186657]. JAMA Netw Open. 2018;1(7):e184587. Published 2018 Nov 2. 

Wang DD, Li Y, Bhupathiraju SN, et al. Fruit and Vegetable Intake and Mortality: Results From 2 Prospective Cohort Studies of US Men and Women and a Meta-Analysis of 26 Cohort Studies. Circulation. 2021;143(17):1642-1654.