I live like this - I'm insulin resistant so this is my day-to-day way of living! Basically you need to eat in such a way that your body doesn't need to produce insulin to break down sugars from your food and drink.
Basic principles:
refined foods produce lots of sugar - so avoid white stuff (table sugar is the worst thing possible) - white bread, pasta, flour, a lot of breakfast cereals are REALLY high in sugar so you may need to rethink this. Porridge? bacon and eggs? Wholmeal pasta and brown rice are fine, but try not to make them the whole meal - ie have a portion of rice with a larger portion of protein. Soya and linseed bread is the best for eating low GI, which is basically what this diet is.
Lots of protein - my consultant's advice is 'if in doubt, eat meat'! Lots of meat, cheese, eggs, oatcakes (these are my saviour - I always have them in my bag with babybel)
Avoid fruit juice (it's basically liquid sugar) - I'm afraid that really it's water or wine - if you have a tipple, avoid beer and cider as they are full of sugar. Champagne is fine!
Careful with some veg - parsnips are high in sugar. Avoid potatoes - squash and sweet potato are better.
Basically make sure that every time you eat, a bit of protein hits your stomach first. the more protein you eat, the better your body can cope. Remember nuts and seeds, and remember that milk is a protein and also sweet.
If you can, substitute sugar for fructose ('Perfect Sweet' in Sainsburys and Waitrose) - it tastes pretty much the same but you won't have to put your body through any hard work to break it down. hot chocolate with fructose, dark chocolate powder and milk is a real treat for me and perfectly fine.
You will also find after a few days (during which it might feel a bit weird as you're not hungry but you're craving something sweet - RESIST if you possibly can!) that your sweet tooth starts to decline. some really good quality ice cream isn't too bad after a meal as there is so much fat there that by the time your body comes to deal with the sugar, the protein hit from the cream has kind of offset it (avoid sorbets though as they are all sugar and no fat.)
Exercise as much as you can - even just 15 minutes walking is great - as it aids insulin effectiveness.
Careful with caffeine - including diet coke etc, as it makes the body behave as though there is sugar present.
I can't vouch for this way of eating enough - it brought back my waistline (now donated temporarily to the baby), cured my PCOS (insulin resistance is the cause of it), helped me sleep more deeply, feel better about myself, cleared up my spots, made my hair thicker, and ultimately ensured that I got pregnant. I promise that if you can do this, you will feel fabulous for the rest of your pregnancy! I'm convinced also that it's why I didn't get morning sickness etc - I don't get the sugar slumps that cause cravings or make me hungry - all this kind of food burns off slowly.
good luck!