My dad getting tired please help?

My dad is getting tired and he is a diabetic but his blood test says his blood glucose B12s okay and he takes iron tablets and his iron levels are okay his overweight and does not excercise and his BMI is 31.6. He is also a vegetarian and doesn't eat eggs. Can someone help with this question, and give some vegetarian dishes and some ideas to why he feels drowsy 24/7?