I just turned 41 on Saturday and this is my first attempt at dieting after age 40. Sadly, I didn't bother last year. Fortunately for me, my youngest child keeps me busy and I haven't gained any additional weight over the past few years.
But, it is going to be harder for me to lose weight now, than say at 35? I'm an Atkins fan and am starting induction today.
As you age, you aren't able to eat the same unhealthy foods you used to without detrimental results to your weight.
Your hormone balance changes and may make it easier for your body to retain weight.
You’re also busier, with kids, work, chores and activities, and sleep often gets pushed aside as being important for your personal health.
For me, after 40 is when everything started going downhill....
I got my first injury at 41, an achilles tendon rupture, and I have been feeling more sore in general from workouts, and some pains here and there from extrenous activity. I wasn't like that in my thirties, my body recovered quickly.
But on the plus side, I have started doing weight training after 40, and I am stronger that I have ever been in my life!!!
So it all depends on you. 40 is not the end of it. You can certainly do it, if you put in the effort!!!
I think about this a lot. When I lost 120 pounds, I was between ages 37 and 40. I've since but about 45 of it back on, and now that I'm setting out to shed that regain, I am turning 45 this year. Five years older, five years slower metabolism, five years more wear and tear on my joints making it more difficult to exercise hard. (And maybe, when I squint at it, the occasional sign of perimenopause here or there.)
I've been trying to prepare myself for the reality that it's going to be slower this time around. The last 20 were slow enough last time - that took about a year - and I have to be prepared for 20 pounds a year to be the best I can do at my age.
Some of the things I tell myself to deal with the reality that it could be two years of hard, disciplined work before I get back to where I want to be: Well, time goes by very quickly these days. A year ago seems like yesterday in many ways. Since the time will pass anyhow, and pass fast, I may as well spend it losing weight, even if it's not as fast as I would like. Also, if I put on 20 pounds in a year, I would be horrified at the gain. So conversely, if I lose 20 pounds in a year, I should be delighted with the loss.
Oh, it's definitely not impossible. I did it several times, lol. People do tend to lose muscle as they age (you can buck that trend with effort) and that is one thing that lowers metabolism. For women, menopause or peri-menopause also have effects.
However, I think a lot of people who notice that it's harder to lose weight as they get older may be noticing the effects of "metabolic adaptation." If they've lost weight before, their metabolism adjusts to deal with the perceived famine -- and stays adjusted for a long long time. To the OP, since this is your first time losing weight, you won't face this problem initially. But before you start any program please research the issue of metabolic adaptation and try to mitigate it.
I think its harder for women to lose weight after 40 then men they do not seem to have the same issues with hormonal problems that we do
Yes it gets harder as you get older put muscle building workouts in to help you loose
For me personally I have not found it to be harder after 40. Actually I am finding it a bit easier. I seem to have the motivation and will power now that I lacked in my weight loss attempts when I was younger.
How much worse after 40?
and this is my first attempt at dieting after age 40. Sadly, I didn't bother last year. Fortunately for me, my youngest child keeps me busy and I haven't gained any additional weight over the past few years. 
