I'm looking at starting a regimen combining the Practical Programming strength training routine (a derivative of the Starting Strength program) with the Couch to 5K running plan, in order to improve both strength and cardio. Now, I've seen some great diet plans for strength training or running, but I cannot determine an appropriately balanced diet for this approach.
Entry level 5K training involves very little caloric consumption overall. Plenty of strength athletes are doing ~10 miles a week just as a part of basic conditioning. If you move to half marathons then you need to start being more careful.
From the Couch-to-5K website:
The final workout! Congratulations! Brisk five-minute warmup walk, then jog 3 miles (or 30 minutes).
So the final workout consist of a 3 mile run, and some quick math says that's around 450 calories at a fairly aggressive pace. So if you were running that three times a week (which is way more than the training plan suggests), you're looking at ~1200 calories a week, or 171 calories a day.
I would follow a strength training diet, emphasizing protein and high quality fats while minimizing carbohydrates. I'm a fan of Lyle McDonald's work in the topic. If you're really going to do a race and want to make sure you're in top form, have some pasta for dinner the night before.
Based on your objective of fat loss whatever diet you follow should result in a caloric deficit of some sort. What that means for you will vary based on how much exercise you get both in a strict sense (at the gym or on the track) and a broad sense (do you sit at a desk all day or do you herd cats for a living).
Seeing that you want to gain muscle mass your diet should be rich in plant and lean animal proteins (i.e. legumes, grains like quinoa, chicken, turkey) and healthy carbs (whole grains). Healthy fats (avocados, nuts or fatty fishes) are also good and important because they facilitate a healthy metabolism but should be consumed in moderation. Eliminate unhealthy fat and refined carbs. That fried twinky isn't a good idea and neither is that slice of pizza and you know it.
Healthy eating is not rocket science. Stick to whole, unprocessed foods. Read your labels and understand what you are eating. The Whole30 diet has a great guiding principal in that regard: Read your labels and if you do not know what an ingredient is or does or where it comes from pass on it.
