The diet plan marketed by the United Sciences of America, Incorporated (USAI) claims to offer "optimal nutrition" for the health of Americans. This claim raises the question, what is an "optimal" diet? Analyses of the four diet products--a fiber energy bar, an omega-3 fatty-acid concentrate, a calorie-control formula, and a master formula of mixed ingredients--raise questions regarding safety and efficacy of this plan. Still further questions focus on endorsement of the USAI diet plan and the relation of endorsement to receiving "grants" from the producer.