You don't need to over compleicate a size and strength diet. Get the basics right first and then progress, just like with a training routine.

Important rules for weight gain:

• Eat 6 (+) meals a day.
  

• Reduce or completely cut out alcohol intake.
  

• Have one treat per week, TO KEEP YOU SANE
  

• Replace fizzy drinks with fruit juice, cordial, water.
  

• Drink milk, but not skimmed as this has the fats vital for muscle repair removed.
  

• Each meal must contain protein for muscle repair and carbohydrates for energy.
  

• Drink a coffee pre-workout for an energy boost, of needed or an energy based suppl
  

• Pre-workout: Meal containing protein and carbohydrates or supplement.
  

• Post workout: Meal containing protein and carbohydrates or meal replacement shake (Supplement)
  

• Drink a milk based protein drink before bed to aid muscle repair whilst sleeping.
  

• Take supplements for best results
  
  

PROTIENS

• Egg whites
  

• Chicken
  

• Turkey
  

• Fish
  

• Beans
  

• Red meat (once a week max)
  

• Peanut butter
  

• Cottage cheese
  

• Vegetable proteins e.g. Quorn
  

• Nuts / seeds
  

• Legumes
  

• Soya products

CARBOHYDRATES

Carbohydrates as natural starches are found in:

*Complex carbs: Slow release energy and main mass builder

*Simple Carbs: Fast source of energy and used for vital nutrients and fat loss.

• Bananas (fruit)
• Green Vegetables (great for fat stripping)
• Salad
• Barley
• Beans (Also have high protein properties)
• Brown rice
• Chickpeas
• Lentils
• Nuts (Also have high protein properties)
• Oats
• Parsnips
• Potatoes
• Root vegetables (Mixed)
• Sweet corn
• Wholegrain cereals
• Wholemeal breads
• Wholemeal cereals
• Wholemeal flour
• Wholemeal pasta.

Supplements 

• Herbalife Formula 3 Protein powder & Formula 1 Meal Replacement

• HMB or BCAA capsules – Helps prevent muscle loss after training and during cardiovascular exercise.

• Creatine powder (Take with water and glucose powder) – Helps increase muscle mass, strength and endurance.

• Creatine capsules - Helps increase muscle mass, strength and endurance. Can also be found with additions like energy boosters.

• PhD Nutrition Synergy – All in one supplement. Can personally recommend this product as a cost effective, easy taking product, which with the right training can produce great weight and strength gains, fast.
  

• Reflex meal replacement – Great source of nutrients if you don’t have time.

• Whey Protein – Key to muscle building pre, post workout and before bed.