Lethargy after eating

Hi

I know most people feel lethargic after eating but I think I am effected more than most. I am seventy four years of age but first became aware of the problem in my twenties when I found consumption of even a small amount of food made any sort of moderate to heavy exercise extremely difficult but could handle light exercise. I now have difficulty walking anyway, some day worse than others but if I eat even a light meal walking even a short distance exhausts me.

I have to concede I am overweight, some fourteen stones whereas ten to eleven stone would be more ideal. Hence my need for exercise.

If anyone has thoughts regarding this I would be most grateful for them.

Best regards Ken.