Seems like you could stand to gain some weight, as right now it doesn't look like you're eating much. You could do with some variety, mushrooms and baked beans twice in a day? Try some spinach, tomatoes, carrots, broccoli, apples, oranges and so on. Have some fruit and plenty of vegetables, plenty of variety. Eat unrefined carbs (brown rice, stoneground bread, wholemeal pasta), lean protein (seafood, chicken, turkey, game meat, beef, pork) and unsaturated fats (unsalted nuts, particularly almonds and walnuts, avocado and oily fish). You're drinking plenty of water which is good, try to keep intake of sugar, saturated fat, condiments, juices, soft drink and processed foods to a minimum.

Don't forget to throw in some basic bodyweight movements to prepare yourself, pullups, pushups, situps, dips, handstands, lunges, step ups and so on, and once you progress beyond that, start doing some weightlifting and powerlifting. Running is important for the army, as well as some pack marches, so once you've got some running ability, wear a backpack filled with some weight (books, sand, rocks).