It is completely true that losing weight often feels harder in your 40s, 50s, and 60s than it did in high school, college, or your 20s.
At this point, you might be thinking the answer is to start acting like you are 18 again.
Maybe sign up for a college course, get some extra steps walking around campus, and sit through a 3-hour lecture without food.
Hell, break out the old Led Zeppelin records while you’re at it.
But maybe this time around, skip the dating drama and keg stands. 
A lot of people assume their metabolism has dropped.
That is usually not the full story.
Research has shown that, after accounting for body size, energy expenditure stays relatively stable from ages 20 to 60, with more meaningful decline showing up later in older age.
So why does it feel harder now?
For most people, the biggest reasons are these:
1. You move less than you used to
When you were younger, you were often active without trying.
You walked around school.
You walked around campus.
You were on your feet more.
Even when you were at parties on the weekend, you were likely dancing for hours and accidentally burning an extra few hundred calories.
Now many people sit for most of the day, drive more, and have far fewer built-in chances to move.
2. You have more access to food than ever
As an adult, you have more money, more freedom, and more chances to eat out.
There are more restaurant meals, takeout options, snacks in the house, and opportunities for mindless eating.
3. Your life now comes with more food-centered events
Kids’ birthday parties.
Adult birthday parties.
Barbecues.
Pizza nights.
Desserts.
Work lunches.
Networking dinners.
Drinks with clients.
Weekend get-togethers.
These things add up fast, and they often happen more now than they did in your teens or 20s.
4. You may feel less pressure to stay lean than you did when you were younger
When you were younger, you may have cared more about impressing people, fitting a certain image, or looking a certain way.
Now, many people care a little less about that, which is likely a net positive.
But it can mean there is less daily pressure helping keep eating habits in check.
5. Your environment makes overeating easier
There is food at work.
Food in the kitchen.
Food on the way home.
Food at events.
Food while driving.
Food while watching TV.
A lot of adults are surrounded by easy calories all day long, and that makes staying in a calorie deficit much harder than it used to be.
That is why losing weight can feel harder now.
Not because age means you are broken.
Because your weekly activity is lower and your weekly calorie opportunities are higher.
That is also good news.
Because it means there is something you can do about it.
If the problem were only age, you would be stuck.
But if the bigger issue is lower activity, more sitting, and more high-calorie situations, then those are things you can improve.
Walk more.
Strength train.
Be more aware of dinners out.
Be more aware of weekends.
Be more aware of liquid calories, snacks, and mindless eating at home or at work.
Takeaways:
1. It often does feel harder to lose weight as you get older, but the biggest reason is often lifestyle, not just age.
2. Most adults move less and have more chances to overeat than they did when they were younger.
3. Your environment now makes it easier to eat more and harder to stay active.
4. That is good news, because activity and eating habits can still be improved at any age.
– James Pratt