I used to have problems gaining weight but changing what I eat helped.
One thing for me is that if I eat carb heavy my body burns it quickly but it also does so with low carb foods.
I need to combine protein, good fats and a moderate amount of carbs to gain, look well and feel my best.
I eat more meat and eggs than the average person and it eat both daily (about 250g). I add calories from grass fed butter, fatty nuts, avocado. I eat some dairy here and there as well. Combine all that with carbs and I gain weight. Especially the butter really adds calories.
I personally eat Paleo or at least Gluten free but weight gain would work with bread too if tolerated.
Maybe I should try this...right now I have been focusing on lots of fats and carbs because I really thought that would do it, but not so much so far. How many eggs per day do you recommend? How do you get in enough fruits and veggies?
I basically don't eat any pasta or bread and rarely rice or Gluten free products which leaves lots of extra room for fruits, veggies, meat, dairy and eggs (and is more nutrient rich over all too!) I used to think a ton of carbs would help me gain, plus adding more fats...but it turned out the carb to fat ratio was still too high. I also wasn't eating meat in the past. I eat about 4 eggs a day and the fats I eat are saturated fats. I personally do best with butter so I used to eat home made pancakes based on nut flour every day, topped with slices of butter and honey (will try to attach a picture)
Eating less of the extremely carby foods and being on this diet has normalized my metabolism over the years so I need to eat far less nowadays to maintain my weight
If you tolerate dairy well, full fat yoghurt, milk and cheese are a yummy snack. For even more calories heavy cream could be added to yoghurt.
Some nuts like macadamia and brazil nuts have a lot of calories.
Potatoes aren't Paleo but when trying to gain weight they definitely helped me. Sweet Potato is the Paleo alternative. I used to add butter.
Reduced carb intake is also a way to keep a high fat diet healthy...a high carb diet combined with fats, possibly even bad oils like canola is a receipe for disaster. I also don't eat sugar unless I make an exception. Many foods can be sweetend with honey, I even bake sugar and grain free
Hope that wasn't too confusing.
I actually gained too much so far. At 15 weeks I was 6 lbs over the max. and now I am 4lbs over, though visibly I haven't changed ^^. I have been having a great appetite all pregnancy.