I have an extremely fussy DS1 and a not quite as fussy DD. I know alot of people say measure with the clock - but I actually find the opposite works for us. I will give them whatever meal, and they cannot have anything different, any treats until theyy have eaten more then 2/3 of that meal. That meal will not be taken away until it is time for the next meal. My DS1 will literally be eating breakfast until lunch time somedays. My DD is really not that bad at home now (since we have started doing this) and has even started eating her vegies and meat at my parents, because she knows that I won't let her have whatever treat nanna has for her until she has eaten dinner.