Older women

Even if you decide to go vegetarian, you still need adequate protein, especially as you age. You will need to account for loss of B12 if you go vegetarian, but you still need the same amounts of protein - just from plant sources. If you prefer not to eat meat, I would suggest doing some research on vegetarian nutrition needs and supplementation.

I don't eat a lot of meat, but I do get to my 20% goal and exceed it most days. I do eat eggs, dairy and nuts and legumes. Whole grains have protein too. I also use both whey and plant-based protein powders on my busier or more active days.

Start by hitting your 20% protein goal given to you by Myfitnesspal.

It's not "vegetarian or protein"!

I've been vegetarian for 47+ years, thin to fat to obese and back again. Vegetarianism is irrelevant to body weight - a complete tangent.

Nowadays, formerly obese, maintaining weight at 5'5", mid-120s pounds, active, age 66, female, still vegetarian, my personal protein minimum is 100g, and I usually exceed it.

If anything, vegetarians need more protein than meat-eaters, because most plant-based protein sources are less complete (in terms of essential amino acids) than animal sources. For vegetarians, getting more grams of protein is a bet-hedge, along with varying the plant sources within a day or few.

Aging people, research now suggests, need to spread protein through the day more than young people do. Here's a mainstream source for that, quite detailed and informative:

https://www.jamda.com/article/S1525-8610(13)00326-5/fulltext#tbl4

In my opinion, an omnivorous diet - i.e., one including meat - makes it slightly easier to get good nutrition. I see no nutritional/health justification for being vegetarian or fully-plant based. Clearly, I think there are good reasons to go that route, but they aren't IMO weight management, nutrition, health, or athletic performance . . . no matter what some so-called "documentaries" or blogosphere advocacy sources say.