It all depends first in which setting you plan to play. The way I see it (general D&D vision) a halfling is just a smaller human 90 to 110 cm, a dwarf is 135-150 cm. The chubby style is more hobbittt'ish than halfling'ish. If you play a reglar D&D halfling he is not chubby pere se, he'l be just like a regular human so he can be slim or chubby. Same thing with the Dragonlance Kenders they are also 90-110 cm