“Obesity incidence starts increasing in one's twenties and peaks at 40 to 59, and then decreases slightly after age 60,” says Craig Primack, MD, an obesity medicine physician at the Scottsdale Weight Loss Center in Arizona.
Men tend to gain weight until age 55, and then slowly start to lose it in the years that follow. This could be because men produce less testosterone after this age. Women, on the other hand, usually stop gaining weight once they hit age 65.
Those extra pounds were packed on in early adulthood: The average American gained about 17.6 pounds from their mid-20s to mid-30s, the study found. Meanwhile, the average person gained about 14.3 pounds between their 30s and 40s, 9.5 pounds between their 40s and 50s, and 4.6 pounds between their 50s and 60s.
Weight gain is common as we age. As you move through your 20s on to your 30s, you may notice subtle changes in your waistline, and an increasing tendency to gain weight. We should however be mindful that metabolic rate does change as we get older because of the decline in our muscle mass.
Summary: Many people struggle to keep their weight in check as they get older. Now new research has uncovered why that is: lipid turnover in the fat tissue decreases during aging and makes it easier to gain weight, even if we don't eat more or exercise less than before.
If a person has a high metabolism, they may not gain much weight even when eating high-energy foods. Frequent physical activity. Athletes or people who engage in high levels of physical activity, such as runners, may burn significant amounts of calories that result in low body weight.
“Metabolic rate is really stable all through adult life, 20 to 60 years old,” said study author Herman Pontzer, an associate professor of evolutionary anthropology at Duke University and author of “Burn,” a new book about metabolism.
Study shows that younger people and women are more likely to put on extra pounds. A study that examined the long-term weight gain of more than 13,800 U.S. adults found that on average, people gained about 17 pounds between their twenties and thirties.
Epidemiologists have observed that the average person typically puts on 1 to 2 pounds a year from early adulthood through middle age.
As you age, your muscle mass decreases and your fat mass increases. Fat is less metabolically active than muscle—you don't need as many calories to maintain fat as you do to maintain muscle. Hormonal changes can also lead to weight gain.
As you get older, your metabolism starts slowing down - meaning you don't require as much energy to fuel yourself, despite still having a 25-year-old's appetite. And when your muscles can't metabolise energy efficiently, you're more likely to put on weight.
"Many people in their 20s might thus notice subtle changes to how their body is shaped or rests compared to when they were in their teens," adds Dr Kennedy. "It's natural and normal to notice slight incremental weight gain as we move through the mid to late 20s."
You can now blame your bones. Most people don't grow any taller after the age of 20, but a recent study published in the Journal of Orthopaedic Research found evidence that the pelvis -- the hip bones -- continues to widen in both men and women up to about age 80, long after skeletal growth is supposed to have stopped.
Your metabolic rate peaks in your early 20s, according to Women's Health Magazine. At this age, you tend to have a higher muscle mass and have a fair amount of physical activity built into your day.
New study says decline begins in our 50s
Researchers with Duke University's School of Medicine suggest that physical decline begins in the decade of the 50s and worsens as we age, especially for those who don't exercise.
Your metabolic rate does change during your early life, but it plateaus between the ages of 20 and 60, and only decreases by around 1% per year after that. Your total daily energy expenditure also depends on your weight.
If your BMI is: under 18.5kg/m2 – you are considered underweight and possibly malnourished. 18.5 to 24.9kg/m2 – you are within a healthy weight range for young and middle-aged adults. 25.0 to 29.9kg/m2 – you are considered overweight.
Add extras to your dishes for more calories, such as cheese in casseroles or nut butter on whole-grain toast. You also can add dry milk or liquid milk to foods for extra protein and calories. Some examples are mashed potatoes or soups. Try smoothies and shakes.
“Yes, it's definitely more difficult to lose weight as you get older,” says Kim Larson, registered dietitian and spokesperson for the Academy of Nutrition & Dietetics. “There are so many physiological changes as you age, through your 30s, 40s, and 50s.