I'm trying to put together a nutritional plan for myself for weight loss combined with cardio to keep me healthy and active, but am finding it difficult to incorporate fibre without overdoing the carbs. The cardio I am doing is stationary bike, and running.
Which foods are high in fibre yet low in carbs that would provide adequately for my exercise plan?
This is indeed a truly difficult task. When counting carbs for your diet it helps (a little) to know that your body can't process dietary fibre. That means you can subtract the grams of fibre from the total grams of carbohydrates. You can't do that for any other item on the nutrition label. That number is the true net carb for the food.
NOTE: your lettuce/cabbage has very low calories and generally runs 1g fibre/100g product -- 1g net carbs. It's a good filler.
You are going to get your best results in the dark green vegetables. The good news is you also get a number of vitamins and minerals your body needs from these vegetables. Unfortunately, you won't find anything with an incredible 9g fibre that doesn't have a commensurate amount of other carbs. Something you may do while you are cutting carbs is to use Fibre supplements. I've been able to find some that give me 4g fibre/serving with a net 2g carbs. That can help a lot.
Generally speaking, it seems that beans and many veggies are high in fiber. Most fruits I searched were in the 10-20% range. Here are my initial findings:
Barley (~23%)
Be aware that there are two types of fiber out there - digestible fiber and indigestible fiber. Digestible fiber comes from the fiber in and attached to starches and sugars, mostly. Think the fiber in whole-wheat bread and brown rices. You do NOT want digestible fiber if you are looking to increase your fiber intake. I bring this up so when you see 'fiber' on a loaf of bread, you'll know it's not the fiber you want.
What you're looking for is more indigestible fiber - cellulose and lignin - to increase your gut mobility and water retention. The best foods for these are green or fibrous vegetables.
You may have just gone ugh! in your mind, but there are a lot of people who initially have that reaction that end up loving their veggies once they realize what's out there. The salads you're most familiar with are overwhelmingly likely to have paper-like lettuce beneath twice-frozen carrots, preserved cherry tomatoes, and other such poor-quality ingredients. If you get yourself some fresh, organic baby spinach and toss it up with sliced strawberries, chopped almonds or cashews, and dust it lightly with feta crumbles, your tune toward a salad could change very rapidly indeed.
You can check out this page to give you some idea of where to start, but if you don't see something you want right away, just google for 'high-fiber vegetables' and you'll get all sorts of information.