Background <p>Mental health challenges, including anxiety, stress, depression, sleep disturbance and cognitive deficits, are prevalent among athletes due to continuous overtraining or field stress. Pearl millet is a nutrient-dense grain rich in lipids, iron, dietary fibre, and B vitamins and has potential benefits for mental well-being and improved cognitive function. Hence, the present randomised controlled trial aimed to study the effects of pearl millet diet on serum micronutrient status, mental health (anxiety, depression, and sleep disturbance and disordered eating behaviour) and meta-cognitive skills in athletes.</p> Methods <p>Male athletes (n = 60) aged 18–25&#xa0;years were randomly allocated to experimental (EG) or control (CG) groups. The EG was provided with 1/3 of a pearl millet diet in lieu of regular cereals (wheat/rice) for 60&#xa0;days, and the CG continued with a regular diet. Pre- and post-test blood samples were collected for biochemical analysis (haemoglobin (Hb), serum ferritin, folate and vitamin-B12); mental health and meta-cognitive skills were determined via the SMHAT-1 and MCSS, respectively. The effects of the pearl millet diet on the study outcomes were determined via paired and independent sample t tests.</p> Results <p>Compared with the CG, the EG significantly decreased (p = 0.014) disordered eating behaviour and significantly improved meta-cognitive skills in planning (p &lt; 0.046), monitoring (p &lt; 0.041), evaluation (p = 0.024) and total MCSS (p = 0.020). Hb (p = 0.016) and serum vitamin B-12 significantly (p = 0.052) increased in the EG, but the mean difference between the EG and CG was significant for folate (p = 0.031) and Hb (p = 0.003).</p> Conclusion <p>Pearl millet diet decreases the risk of disordered eating, and improves meta-cognitive skills and haemoglobin, micronutrient status in terms of folate and vitamin B-12 in athletes.</p>