The pros all use anabolic steroids.

Doing a lot of walking keeps my legs pretty muscular. Pull ups or push ups for your arms? Or swimming?

Run!
Builds muscle tone in all the right places.

To what do you attribute your muscle loss?

If it’s because of cessation of a known activity or known activities, then resume it or them.

If you engage in a catabolic activity, then give yourself enough of a break from that activity, to allow for completion of the anabolic process.

Do you know why?

10 % body weight loss should be a trip to doctor.

@Brian1946 nothing has changed. I’m just as active as I was over a year ago. I’m eating healthier, though.

I’m wondering if I’m lacking something in my diet? I don’t eat meat, but I get my protein in.

Could be age (atrophy). I’m 48.

@Tropical_Willie, yes, you’re right. I need to get checked out.

Track how much protein you are eating for a few days and see if it’s enough. You need protein to build muscle.

Weights are great. You can also use your own body weight doing push-ups, squats or similar, doing stairs in your house or outside, or evening walking uphill. Leg lifts. Zumba, Pilates, yoga, will help strengthen your muscles, if you prefer some sort of class, but weights are probably the fastest, most efficient way, and most effective way.

Most women don’t have the hormones to build large muscles, but if you focus on strength and staying lean you will get more sculpted.

If you’re eating better, that’s half the battle right there.
You could pick up a set of light dumbells & do exercises with them.
I started with a set of 2,5 and 8 lb dumbells (100 years ago) and got a lot of definition within one month with just those and no bench.
It didn’t take long to get used to those weights so I increased them to 15, 20 & 25 lb dumbells on a bench.
I stayed there for years but since I hurt my shoulder (not from weights but from wiping out) I moved back to 8, 10, & 15s.
So far, so good.
I recommend using them and doing some form of aerobic activity.You will feel great!

Consider Protein shakes . ( I took these shakes in place of breakfast and lunch then ate a normal supper and lost a lot of weight and felt more alive and energetic too.)

I lost 60 pounds ( in 6 months) and worked three jobs where I used all muscle groups, then on days off went hiking up hills ,mountain slopes etc

I tried working out in the local gym but did not like the indoor tedious treadmills, weights
instead I would rather like the natural way by going outdoors and walking , hiking etc

As for strength training I was always picking up heavy books, furniture,in my daily home routine anyways and discovered the added muscle growth then.

Some people like training hard but it detracts from having fun and it reminds me of a military
view of training of which I do not like to be pushed into a cookie cutter gym routine.

I did very well until I had an accident and hurt my back ( vertebrae squashed) and had to take

pain pills of which I learned much too late that Ibuprofen although kills the pain its effects

were a slower metabolism that caused excess weight gain plus due to the inactivity at that time as well.

I am older now but restarting the regime that I did years ago , by eating healthy foods and

hopefully hiking again as our National Park system is returning to a safe trails etc

I prefer outdoors as I can combine photography plus getting in shape effortlessly all the while

getting fresh air and burning off excess weight.

I eat more fruits and vegetables and meat (protein) and cut out all sweets except maybe

once every two weeks I treat myself to one ice cream bar or similar small treat only).

I look back on my life and discovered that the best I felt was when I was actively teaching

‘aerobics( now outdated) and was very healthy, so I am currently working on that goal plus

creative projects in the meantime.

Good luck and congratulations on your weight loss and healthy plan to get into shape but people find what works best for them and I get that. I hope it works out as planned for you.

Have you looked at wearing wrist weights? Don’t go big. 250 grams on each wrist but try to wear them all day. Every move you make you’ll be working muscles just a little bit harder. Getting up from a chair, walking, eating, etc. all will be a little bit more difficult. You will actually be more tired at the end of the day and will sleep better.
It is easy to try.

Eat lots of eggs.

Do not follow same exercise everyday. Do different exercises such as strength training, yoga, body weight, swimming, and more. Also concentrate on protein intake with respect to your body weight.

A diet high in protein is good to build muscle, not fat.