#1

This subgroup of people are not much discussed. They tend to lose weight rather than gain weight so they have no adiposity problems, but they can have muscle atrophy problems. I am part of this subgroup and am interested on how to optimize my tendency to catabolism. Presently, if I leave my instinct rule over my feeding habits, I’ll lose weight very gradually, until hitting a threshold (a setpoint) which is may be too low as an optimum. So, I decided to try the very recent version of ChatGPT5.2 and submit a detailed prompt, as follows. Also, I’m reasoning that when following instinct and losing very gradually weight, this may constitute a natural substitute of Rapamacyn, since a catabolic state means the opposite of growth and proliferation.

EDIT: Probably it was not ChatGPT5.2 which answered me in the first instance. It was a little underwhelming. The answer in the next post is by ChatGPT5.2 and is much better. If the difference is due to the passage from 5.1 to 5.2, that’s a significant improvement. But sometimes strange things happen along the routers.

Please see the link in the next post for Q&A

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#2

I just found the previous answer underwhelming. Especially in consideration of the buzz about the newest 5.2 version of ChatGPT. Now I realize my interface was stuck to the 5.1 version, or maybe there has been a recent rollover. So I asked the same question again. Now the answer is more complete, and I like the introduction. This phenotype may constitute a superpower for longevity but it may mean to walk on a razor’s edge. Very interesting. With this phenotype, priority should be to fight catabolism in muscle mass, bones, and connective tissue.

The phenotype you’re describing—older than 60, generally healthy labs, but low appetite and a baseline drift toward negative energy balance and catabolism—can be a quiet superpower for some aging pathways, and a silent risk amplifier for others. The core tension is this: many longevity-associated signals come from “perceived scarcity,” but late-life robustness depends heavily on preserving lean mass, strength, and physiologic reserve. The same biology can help one axis (metabolic/cancer risk) while harming another (frailty resilience).

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#3

Fortunately I didn’t lose my appetite for eating until after I reached age 80. My subjective feeling for this loss are, reduced sense of smell and taste, increased sense of satiation after only eating a little bit of food.
This is quite common with older people, hence the grocer shelves stocked with high protein drinks like Ensure.

A few excerpts from a rather lengthy ChatGPT report:
Brain appetite signaling changes with age
Aging alters hypothalamic regulation of hunger and satiety.
Key changes
↓ Sensitivity to ghrelin (hunger hormone)
↑ Baseline leptin signaling (satiety hormone)
Blunted dopamine reward response to food

Result:
Food simply feels less rewarding and hunger signals are weaker, even when caloric needs remain.

Bottom line (important perspective)
Appetite loss in healthy older adults is not a failure of the body — it is an evolutionarily conserved metabolic adaptation.
However:
Protein needs increase
Micronutrient density becomes critical
Under-eating accelerates frailty, sarcopenia, immune decline, and cognitive loss

Practical implications (very brief)
Smaller meals, higher protein density
Strong flavors (umami, acids, spices)
Liquid calories often better tolerated
Resistance exercise restores appetite signaling
Address inflammation and oral health

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#4

Desertshores, what you underlined is interesting but it outlines a natural trend of loss of appetite with age, whereas light eaters have usually been light eaters even when younger. I sure was, barring the time when I worked out intensely, this was the only way I could boost my appetite significantly.

It may be however that this issue is exacerbated with old age and it becomes potentially a serious one.

Fortunately, I am not experiencing a lesser reward from food or loss of smell and taste, but I satiate easily neverhteless.

#5

I can’t characterize about being a light eater when I was young except that I was never very hungary. I was on the thin side until I reached 40. I was somewhat overweight during my 60’s because my job became sedantary with little oppertunity for regular exercise. I am now on the thin side with no appetite, my current BMI is ~21.

#6

Probably you qualify for the light eater phenotype, they are mostly lean but lack of exercise may result in an excess of calories. Now you unfortunately have the added drawback that, not appreciating fully taste and smell, are losing reward from food hence there is a tendency to eat less.

What is your present strategy to counteract an excess in catabolism? Including protein beverages, are they useful and do they result digestible enough to you?

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