This is our post op diet advice.
Weeks 1-2 Fluids only.
Sips of waters from the day of op. The following day, free fluids. Sip  slowly and frequently, avoid fizzy drinks. Stop if you think you are  feeling full aim to consume 2litres of fluid per day.Made up as follows:
4-6 items from PROTEIN list
As much as you like from Free list as long as you've had at least 4 protein items.
1-2 items from LIMITED list.
PROTEIN list
400mls skimmed / semi-skimmed milk
400mls soya milk with added calcium
2 smooth yoghurts (125geach) to blend with milk to drinkable consistency
1 x 325 can slimfast or other supermarket brand slimming drink eg tesco, boots, asda. 1 sachet or carton of build up or complan
3 Heaped tablespoons skimmed milk powder
15g protein powder eg soya or egg (obtainable from health food shops or a  pharmacy) you may need these to obtain your protein if you do not like  dairy products. they can be mixed into fruit or vegetable juices.
Free List
Water, plain or low cal flavoured (not carbonated)
Low cal,no added sugar squash
oxo, bovril, marmite, miso or stock cubes
soups, tinned, dried, cuppa, home made, dilute then sieve to ensure no bits or lumps.
Coffee, tea, herbal tea
Limited list
150 mls unsweetened fruit juice, dilute and sieve.
200mls veg juice.
100-150ml Vie, actimel or other smoothie drinks, low sugar varieties.
Low cal hot choc, ovaltine, horlicks drinks.
Sample menu
8.00 am 200mls tea/coffee/squash or water
9.30 200mls slimfast, build up, complan
11am 200mls bovril
1.30 slimfast build up complan
3pm 200 mls milky coffee
4.30 200ml soup, no bits with 1.5 tblspns skimmed milk powder
6pm 150 mls veg juice
7.30 200 mls soup, no bits  with 1.5 tblspns skim milk powder
9pm 200ml milk
10.30 200mls low cal ovaltine made with milk.
No time left for housework!!
Weeks 2-4 Pureed foods
Make purees very runny, low fat yog such as muller light, low sugar  custard, soup, mashed veg with gravy, parsley or other sauce for  flavour.Stewed apple, tinned fruit not in syrup, weetabix, ready brek  with lots of milk. After tolerating very sloppy puree for a few days  think about adding protein food such as meat, fish, chicken, lentils and  eggs. All foods should be pureed and low fat, low sugar.
Texture should be like baby food, a good test is it should pour off the  spoon.\Use a food processor or a hand held blender. Use a sieve and  spoon to remove lumps and pips. Add extra fluid to get a smooth  consistency.
Size of meals
1-2 tblspns no more than 5-6 tblspns, eat slowly and take small  mouthfuls. You may find it easier to purchase and puree ready meals   such as shepherds pie or fish pie. A one person meal will usually be  sufficient for 2 meals at this stage. Becaus emeal size is small, you  will need 3 meals and 2-3 small snacks. 
DRINK
1.5 litres water every day. do not drink with meals, 100-200mls about half hour before meal then not until 1 hour afterwards.
Sample menu
breakfast
One weetabix with milk or 125g pot yoghurt or fromage frais or 3 tbspns oats, ready brek  oatsosimple.
Lunch
cup smooth soup or scrambled egg
Dinner
pureed fish pie or shepherds pie or chicken in white sauce and veg.
 snacks
custard with stewed apple or mashed banana  or yoghurt or fromage frais.
WEEKS 4-6 SOFT FOOD
continue eating the same sort of food you were for the first four weeks  but it doesn't need to be pureed, mashing it will make it the  consistency of toddler food. It should still be soft and keep to the  same small quantities and eating 4-5 times per day. Make sure you chew  every mouthful very well. Aim to include 6-8 of the protein items below.
1oz 30g cooked meat, fish, chicken, offal, quorn, tofu
1 egg
30 g grated cheese or low fat soft cheese or cottage cheese.
60g lentils, pulses, peas, kidney beans etc
1/3rd pint milk
1 diet yoghurt
After the first 6 weeks
you are now ready to continue your long term eating plan. Remember, you  are not just eating small amounts to reduce your calorie intake and lose  weight, but aiming for a nutritious eating plan as well. Everyone  differs in the foods they tolerate, but there are a few golden rules to  follow after a gastric bypass:
AVOID HIGH SUGAR FOODS. 
sugary foods can cause dumping syndrome
Eat 3 SMALL MEALS A DAY
You should be satisfied eating 3  meals a day without getting hungry  inbetween. Beware of developing grazing eating patterns of small snacks  through the day.
EAT HEALTHY SOLID FOOD
Soft food slips down easily and you can end up eating more over the  course of the day. Mnay soft foods are high in fat or carbohydrate and  as a consequence you may be taking more calories and your weight loss  will slow down or stop. Choose foods without much sauce and you will eat  less and remain full for longer.
ALCOHOL
This is full of calories and for optimum weight loss and maintenance is  best kept to the rare occasion.After bypass it is also absorbed more  rapidly into the bloodstream so it's effects are felt more quickly, take  care.
EAT SLOWLY, CHEW WELL AND STOP AS SOON AS YOU FEEL FULL.
Many people are used to rushing their meals and as there is a time lag  from stretching the wall of your stomach and telling your brain you are  full, you need to be careful or risk pain and vomiting. Take tiny bites,  cut up meat to the size of a pencil tip rubber and chew each piece  10-20 times. Once you start to feel full, stop eating.
KEEP YOUR FLUIDS INTAKE UP.
Prior to surgery a lot of your fluids will have been obtained from  meals. But with eating smaller quantities you need to increase your  fluid intake. Drink half an hour before eating then leave about an hour  after. If you drink immediately before a meal you may find you are too  full to eat your meal. Fizzy drinks cause bloating and discomfort so  best avoided.
Keeping healthy
There are 5 main food groups and a healthy eating plan comprises a mix of them.
Protein foods- such as meat, chicken, fish, eggs, beans and  pulses-include 2 to 3 60-90g (2-3oz) portions per day.You have to be  particularly careful to chew meat chicken and fish before you swallow  it.
Milk or dairy-choose low-fat cheese, skimmed or semi skimmed milk and  low fat or diet yoghurts. Aim for 3 portions a day to give a good  calcium intake.
Fruit and veg.
Try to have 2-5 portions a day. A small glassful of unsweetened tomato  juice counts as i portion. salads and green veg are easily digested.
Carbohydrates-bread potatoes and cereals-2 portions per day. For many  bypass patients this group is somewhat harder to digest so you naturally  develop an in-built mechanism of reducing your carb intake. Replace  soft bread with granary and wholemeal or crisp breads which are easier  to digest. One small portion 60-90 g at each meal will be fine.
Fats and sugary foods 
Use a small amount of olive oil for cooking. As mentioned above, avoid  the calorie laden food such as chocolate, sweets or ice cream which can  cause dumping syndrome.
Sorry it's like a book!!!