Just about every respected weight lifter is going to tell you that if you want to gain weight, you can't eat clean all the time. Rippetoe, Wendler, Tate, Starr will all say the same things. You'll get some quite colorful epithets to get you to eat junk.
There's some truth to this. First, junk meals tend to have a pretty high fat content. Fat packs in 9 Calories per gram, compared to both carbs and protein which weigh in at only 4 Calories per gram. It's good that you have a high protein diet, and that will serve you well. Second, many junk foods are composed of things that make you hungrier. The combinations of sugars and stimulants (like caffeine) put your body through metabolic hell, but the end result is you will be able to eat more when you consume junk.
It will add pounds. It may not be 100% the type of pounds you want, but you will have them.
There are different approaches. The people I mentioned in the beginning paragraph ascribe to the bulk/cut approach or most of them simply just bulk. Martin Burkhen from LeanGains.com uses the approach of bulking by starting with your maintenance Calories. The quick estimate would be 15x your total body weight. He then has you calculate your macros for training days and rest days. You will be eating higher than maintenance on both days, but increasing much more on training days.
There are a couple major aspects to this approach:
- You are fasting 16 hours and eating all your food within 8 hours
- You are eating 3 large meals rather than several small meals throughout the day
- The largest meal should be the one right after you train
This allows you to actually be hungry enough to eat all your Calories. It's also not dependent on junk food as the conventional wisdom is. The key is you have to find something that works for you, and your goals.
Dealing with Bloating
Bloating is a common side effect of eating some types of carbs. You will have to experiment to see what is the culprit. Many have reported that gluten is a major culprit with bloating--particularly the bloated feeling. High sodium content in your meals can add to bloating, although not with the same feeling as other sorts of carbs.
It's because of this association that many have jumped on the Paleo bandwagon. I'm not pro- or anti- paleo, but it may be worth looking at the types of foods that they have you avoid and experiment to see if they are the culprit for your bloated feeling. If that works, great! If not, try something else.