Global food problems have challenged organizations to explore the possibility of using neglected aquatic plants as supplementary food. This study was aimed to characterize nutrients, antinutrients, phytochemicals, and antioxidant capacities of water lily (Nymphaea lotus). Ethnobotanical survey identified four macrophytes are edible by the local communities. The lethal dose of N. lotus extract was greater than 5000 mg/kg. The highest protein content (23.6%) was found in rhizome of N. lotus. Higher amount of potassium was found in stem of N. lotus (30400 mg/kg) and rhizome of Arundo donax (16600 mg/kg). Leucine was the most abundant essential amino acid in all of the samples while methionine was found in the low concentration. The protein and essential amino acids contents make N. lotus a useful food. The total phenolic content ranged from 0.77 to 5.77 mg GAE/g. The presence of phytochemicals in these edible freshwater macrophyte are great medicinal importance. A higher half inhibition concentration (IC50) of DPPH (24.48 μg/mL), and ABTS (0.4 μg/mL) free radicals scavenging was reported from Typha latifolia. It was concluded that, these edible freshwaters are safe for consumption as the median lethal dose is higher than 5000 mg/kg, and trace metals are negligible. Display omitted •The LD50 extracts of N. lotus was greater than 5000 mg/kg in rats.•The rhizome of N. lotus had the highest protein content.•Potassium was the highest and mercury was the lowest element in all plants.•Leucine was the most abundantly found essential amino acid in all plants.•T. latifola extracts had a higher DPPH and ABTS free radical scavenging activities.