Hard to lose weight after 40 - is this true or a myth?

Definitely harder, but can be done.

100% True! Because as we get older our bodies produce less testosterone if your male which means less lean muscle mass and a slower metabolic rate or slower use of the food we eat as fuel. For women it is the same but the decline of the hormone estrogen contributes to increased weight gain and because of the naturally lower metabolic rate woman have and the monthly "battle" you guys have a harder time keeping the weight down or off. This doesn't mean it's impossible though! Solid nutrition and a good fitness plan. Anything is possible...I hope this helps.

I tend to think, if it's harder, it's because, at later ages, we tend to get more ingrained in the habits that hurt us.

It may be true that our metabolism slows down. But what hurts us is that we're used to eating a certain volume of food and/or certain kinds of food. That's one of the best things about MFP... if you want to lose a pound of week, you can do so by running a 500 calorie a day deficit. I'm approximating of course, but you get the idea. Once you get an idea of what your resting metabolic rate is and an idea of how many calories you burn a day in your normal lifestyle, you can try to adjust those habits to fit your goals.

So yes... I think it's harder to lose weight as you get older. And one reason is because your metabolism changes. But I think, even more so, is because we tend to get even more ingrained with our habits, some of which, we don't know are hurting us.

The older you get the harder it gets. I told my daughter, who is in her early 20s to get moving and she will lose weight fast and easy. I am in my 50s now and it is impossible. 4X at the gym, 14-1500 cal diet. I barely lose 2/10ths of a lb a week. One salty thing and it all comes back. I have an appt with a dietitian next week. I'm printing out everything I log here so she can look it over and make some recommendations. I can NOT do less calories than that without getting evil. I tried 1200 calories and it was not going well at all.

The worst/hardest part for me isn't the metabolism thing -- it's that I get injured more easily and there are more things wrong with me now than when I was in my 20s. By now, I have chronic injuries that are easily irritated - bad back, Achilles tendinitis, etc, plus Hashi's, which didn't start until I was 40. People who believe that they're just getting better as they get older think so because dementia is already setting in.