Abstract Objectives To evaluate the nutrient adequacy of theoretical, modern-day Paleo meal plans relative to the U.S. Dietary Reference Intakes (DRIs). Methods This analysis used data from the Adhering to Dietary Approaches for Personal Taste (ADAPT) Feasibility Study, which captured data on 9 726 self-reported, popular diet followers. Paleo respondents (N = 925) reported sources of recipes and diet guidance. Five days from each of the top six sources were used to generate 30 days of meal plans among a random sample of n = 200 Paleo respondents. Nutrition Data System for Research (NDSR) was used to estimate daily nutrient content of meal plans which was compared to DRIs and recommendations, as follows: recommended daily allowances (RDAs) for vitamins D, E, and folate, which do not vary by age (years, y)/sex; sex and age-specific RDAs for vitamins A, C, calcium (Ca), magnesium (Mg), and iron (Fe); adequate intakes (AIs) for potassium (K) and fiber; upper intake level (UL) for sodium (Na); and Dietary Guidelines for Americans (DGA) upper threshold to limit saturated fat and Na. Results Estimated daily nutrient intakes of theoretical Paleo meal plans met or exceeded RDAs for the following (Paleo vs. RDA): vitamin A for men or women (1481 RAE µg vs. 900 μg and 700 µg), vitamin D (56 µg vs. 15 μg), vitamin E (27 mg vs. 15 mg), folate (489 µg vs. 400 μg), vitamin C for men or women (225 mg vs. 90 mg and 75 mg), Mg for men and women 31–70 y (539 mg vs. 420 mg and 320 mg), and Fe for men (16 mg vs. 8 mg). Theoretical estimates did not meet the following: RDAs for carbohydrate (91 g vs. 130 g), Fe for women 19–50 y (16 g vs.18 mg), Ca for men and women 61–70 y (562 mg vs. 1000 mg and 1200 mg), and AI for K (4027 mg vs. 4700 mg) or dietary fiber (25 g vs. 28 g/2000 kcal). Estimated levels of Na exceeded the UL (2763 mg vs. 2300 mg), saturated fat exceeded the DGA (19% vs. 10% kcal), and added sugar levels fell within the recommendation (1% vs. 10%). Conclusions While certain aspects of the Paleo diet offer improvements over typical reported intakes of US adults, saturated fat is high, and carbohydrate, fiber, Ca, and K levels of these theoretical diets do not meet DRIs. High levels of saturated fat present concern for cardiovascular health. Optimal nutrition may be challenging to sustain on a Paleo diet. Funding Sources Supported by USDA Cooperative Agreements 58-8050-9-004 and 58-8050-9-003.