Many commentators have claimed that farm subsidies have contributed significantly to the “obesity epidemic” by making fattening foods relatively cheap and abundant and, symmetrically, that taxing “unhealthy” commodities or subsidizing “healthy” commodities would contribute to reducing obesity rates. This paper makes three contributions. First, we review evidence from the literature on the impacts on food consumption and obesity resulting from subsidies applied in the past to production or consumption of farm commodities. Second, we develop and present new arguments and preliminary evidence on the impacts of past government investments in agricultural R&D on food consumption and obesity—through research-induced increases in agricultural productivity and the consequences for prices, production, and consumption of farm commodities. Third, we consider and compare the economic efficiency of hypothetical agricultural research policies (changing the orientation of agricultural research investments) versus hypothetical agricultural commodity subsidies and taxes as alternative mechanisms for encouraging consumption of healthy food or discouraging consumption of unhealthy food, or both.