Does caffeine suppress appetite?

Yes, but...: Caffeine is indeed an appetite suppressant and can actually slightly increase your metabolism, and may have a modest effect on weight loss, but there is no hard evidence that caffeine will significantly lead to long term weight loss. Also, keep in mind that too much caffeine can lead to nervousness, insomnia, nausea, elevated blood pressure, and even heart palpitations. Use in moderation.

Caffeine: Yes. Caffeine may suppress your appetite for a brief time, but there's not enough evidence to show that long-term it does anything in terms of help with weight loss. Be cautious about using caffeine when trying to lose weight. When used in moderation, caffeine is generally safe. But too much caffeine can cause insomnia, hypertension, nervousness, nausea, among other problems.