There are multiple strategies in the fight with akrasia. One well-known meta-strategy is the one used by Ulysses against the Sirens, namely, controlling one's future environment so that one's future self is unable to compromise the present self's goals. If we can make it easy on the future self, perhaps this is even more effective. This would be more akin to Ulysses putting bee's wax in his comrades ears, than allowing himself to be tortured but more aware by hearing the Sirens' song while tied up.
Some foods which it seems plausible decrease appetite (further discussion here):
1. Pine nuts
2. Green tea (caffeine free at night)
3. Olive oil separated from meals by at least one hour on both sides (see Shangri La diet ...tried this today and I felt very sick until I ate food one hour later, will re-try with different olive oil)
5. Nicotine (possibly some downsides, especially to the gums...I'm undecided)