Chewing stimulants or placebo herbs to supress hunger in the sbsence of food, but when have to get going looks like a natural habit of people. We see it in South Africains who chew hoodia, and South America where people chew coco leaves. Roughnecks everywhere chew tobacco when cannot get at food. Chewing gum does the same, less stigma and red gums. I guess, we can start chewing mint leaves, but it's a bummer to bring them along all the time.