The first month enables you to be accustomed to your new digestive tract.

Eat very slowly, because you should not fill the small gastric pouch, which is healing.

 

Eat in calm at regular hours.
 Split your food catches in three meals (and, possibly, one or two collations).
Vary your food.
Eat only small pieces.
You must chew lengthily, and swallow several times.
Take time to appreciate your meal. Do not forget that digestion starts in your mouth.
Drink the least possible during your meals..
With the appearance of a feeling of satiety, imperatively cease eating.
Supervise your teeth

One coffee spoon moreover could make you vomit. You have only a mini gastric pouch, do not forget it. 
 
 
If you vomit, try to understand why :
You eat too much.
You eat too quickly.
You eat too large pieces.
You do not chew enough.
You swallow too quickly.  
 
 
Between meals.

Be careful with the dumping syndrom : the ingestion of an unusual quantity of sweetened products can involve a general faintness.
Avoid sweetened drinks and, in theory, aerated beverages.
Often Drink apart from the meals, by small quantity, even without thirst.

Take again a regular physical activity, leisures and endurance. The simplest regular physical activity is walking : walk of a good step but at your own rythm, the ideal being 3 times 30 to 40 minutes per week.
A kinesitherapist may help you. After the first month, you can practise any sport activity.

Respect sufficient hours of sleep.
Possibly make you accompany on the level '' management of stress ''. 
 
A regular follow up by your general practitionar is important.

In addition to your daily contribution in vitamins and trace elements, your doctor will incite you to optimize your food in the direction of a better contribution out of Iron, Calcium,(possibly after a biology of these elements).

You must be also careful with a possible proteinic denutrition. If you do not eat sufficient proteins, you will lose on your muscular masses, whereas it would be preferable to lose on your fat or water of your body. In worst case, you can undergo a protéin denutrition, with fall of immunizing defenses and a tiredness, an anaemia, a increased sensitivity to infections.
 

Eat well and enjoy your life !