Which is better/healthier?

I’ve starting walking at work around lunch time. Is it better for me to eat lunch before or after my 20-30 minute walk?

Ah, I remember this from the original “Aerobics” book. He said to eat after exercise. I think the rationale is that your increased blood oxygenation after exercise will decrease your appetite, you’ll eat less and be in better shape.

It’s always better to eat after exercising. The conventional wisdom is to wait one or two hours after eating before exercising. If the exercise is to consist merely of a half-hour walk, it probably won’t make much difference. The reason is that your digestive system slows down, or shuts down in more exertional exercise, during exercise, as your blood is diverted to the exercising muscles.

It is true that after a hard work-out, you don’t have much appetite right away. Blood oxygenation doesn’t have anything to do with it. Norepinephrine kicks in during such stress as heavy exercising, and that releases sugar from the liver to prepare your body for its need. It’s the lack of sugar in your blood that causes hunger.

Another point to keep in mind is that you will burn more calories if you eat after excercising. With food in your digestive system the body won’t bother mobilising stored energy reserves but will just burn off what’s being digested. This will prevent it being sored as fat, but if you eat after a meal the body will have to use energy to convert existing fat to useable enrgy and then later use energy to convert the digested food into fat.
So if your goal is losing weight go for a walk before lunch.