Fifteen years ago when my husband finally died of Alzheimers I had gained up to 165 lbs. I am currently 83, and 5’3”. My constant weight during my 20s before I got pregnant was 123 lbs. After he died I was trying to loose weight just being careful about what I ate. After one year I was 155 lbs. Then I read a Dr. Atkins diet book, so tried the First Stage diet of no more than 20 gms of carb a day. I was loosing 2 to 3 lbs a week, so stayed on it for about 4 months to about 130 lbs. I did not seem to have any problems.
I did not try to pig out on protein as that can be somewhat dangerous. I don’t seem to be allergic to any vegetables, but for low carbs used mostly leafy veggies, cucumber, celery, and small summer squash, all raw, with small amounts of raw tomato, cabbage, red-yellow-or green pepper strips, and onion for flavor. There are a number of commercial salad dressings that only have 1 or 2 gms of carbs for 2 tablespoons. I have had several periods of high stress (or holiday feasting) when my weight crept up to 145 lbs, but it doesn’t take long to get down to low 130s again, with low carb diet. I like that idea of ancestral foods, and like to go pick berries when I can find them. Last fall there were some nearby mulberry trees that provided good desserts.
Do NOT be afraid of protein .... the older you are, the more you need. Most people do not eat enough. Those trying to lose weight unsuccessfully frequently find out they are low on protein .... if you are low, your body thinks you are in starvation mode so no weight loss. Also, protein is VERY important for building muscle. Again, muscle loss in older folks is when they become ‘feeble’, among other things.
As for vegetables, if you can tolerate them (you don’t get inflammation, GI upsets, etc.), then they are fine. Eat your protein first, then your veggies as a side.
As for Atkins, the man was RIGHT .... low carb is the healthy way to lose weight & is “ancestrally” correct for humans. The poor guy was vilified, called a crack pot, accused of killing people, causing heart disease, etc. Bottom line, Big Ag/Big Pharma had a huge stake in keeping people from discovering the way to good health (which meant coming off their expensive meds, not eating their junk grain-based products) so the purpose then (Atkins) and now with the low carb docs is to vilify, try to jerk their medical licenses, etc. Unfortunately, what has been seen cannot be unseen - people reversing Type 2 diabetes & coming off insulin/BP meds/statins, resolving autoimmune disease, losing weight and living happy, healthy productive lives again.
Congrats on your weight loss & having a successful way to deal with it when you gain a few pounds! You’re way ahead of many people/the curve. PS - again, do NOT be afraid of protein - if you have kidney disease, you’d need to talk to your doc, but if not, there are a lot of good resources on how important protein is, especially for the elderly.
Dr. Gabrielle Lyon is a good resource - emphasized gaining/keeping muscle.
https://drgabriellelyon.com/
Dr. Ted Naiman is also a good resource - here’s an article:
https://www.simplysnackin.com/blog/ted-naiman-pe-diet-book