Hello, Your dad had a massive heart attack so the risk factors should always be taken care of. After a heart attack, high blood pressure, high cholesterol and diabetes should always be under control at all cost both by taking medications and diet control. Healthy lifestyle should be regularly followed, he should quit smoking, alcohol and addictions if any. He should eat healthy food and get active. He should avoid taking oily , fried, junk food, processed and packaged food, trans fat, full fat dairy products, refined flour, red meat, etc. He can take lean meat, small fishes cooked in olive oil, boiled food or food and veggies cooked in olive oil. He can take nuts, dry fruits, well cooked whole cereals, lots of well cooked veggies and fruits (to avoid acid reflux). He can include all heart healthy food in his regular diet, you can also consult a nutritionist. He should take medicines as prescribed by his treating doctor. Should always get follow-up clinical examinations done, cardiac rehabilitation if needed. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician