Hi Nikki, and welcome.
The main rule with Xenical is to stick to under 5% fat per 100g of food, and not more than 15g of fat in each meal....if you do this, you should avoid the tango effect!
I find it useful to count calories, roughly sticking to 1500-1800 each day, but I also keep my eye on the fat content because of the Xenical. Other people follow diets like Slimming World or Weight Watchers, and have great results too. It's just a case of finding out what suits you and your lifestyle.
If you're just going to look at fat content rather than following a particular diet plan, I'd advise you to make sure you're not consuming too many foods that contain extra sugar to replace the fat.
Reduced fat biscuits are one example - they may contain 30% less fat than the original version, but if you look at the packaging, they're almost identical in calories, because of the extra sugar they contain. It's things like this that can potentially sabotage your weight loss, if you're not careful.
Other than this, I'd say make sure you drink plenty (constipation can be a problem, especially early on) and make sure you eat plenty of fruit and veg to fill you up.
What kinds of foods do you like to eat? I must admit, I tend to stick to low fat ready meals and veg in the evening, but I do make batches of food to freeze from time to time, and there are some great low-fat recepies on the Xenical forum if you have a dig around.
It sounds like you've got the exercise bit sorted - I'm no fitness expert, so I can't advise on that! (I hate it!)
Good luck with the Xenical - the side effects really aren't anything to fear, as long as you're sensible with your food, you'll be fine.
Good luck, and let us know how you're getting on
