Hello Sir: Let me try to formulate the guidelines you ask for. Think of everything we tell people to do to lose weight and do the opposite. Increase the portion size of healthy meals. Eat 3 meals and two small high calorie snacks. Consider this: fats have 9 calories per gram; protein and carbohydrate have less than half at 4 calories per gram. Eat a nutbutter sandwich for a snack, make an entire list of high energy snacks that are healthy for you. Avocadoes on a salad or anywhere is equal to 8 fat servings; nuts in general; dried fruits; make high calorie smoothie or beverages like shakes (recipes on internet), increase virgin olive oil in recipes and salad dressings, snack on olives, use dressings liberally. Take a multivitamin every day while repleting yourself. Don t forget to tone your muscles so weight gain does not go to the belly, then that gives you a look you do not want. I would develop a combination cardio and strength training routine and add nutrition to support the exercise. Use arm weights, improvise. You need to add 500 calories per day to gain one pound per week and not Body Fat Gain!! So still stick to lean meats better for the heart or vegetarian proteins. I hope I have answered your question. Thank you for visiting HCM. Kathryn Shattler, MS,RDN Registered Dietitian Nutritionist, USA