Eating wholefoods past satiety is very hard and uncomfortable. Processed foods override satiety via the reward system.
"I think the basic anti-aging diet is also the best diet for prevention and treatment of diabetes, scleroderma, and the various "connective tissue diseases." This would emphasize high protein, low unsaturated fats, low iron, and high antioxidant consumption, with a moderate or low starch consumption.
In practice, this means that a major part of the diet should be milk, cheese, eggs, shellfish, fruits and coconut oil, with vitamin E and salt as the safest supplements."
- Ray Peat
I think what it does is normalizes your weight, someone eating the SAD may be underweight because they are not susceptible to processed foods but they are underweight because of malnourishment caused by white flour and vegetable oil and the Paleo diet fixes that. However the OP seems to be eating a wholefoods diet already and is exceptionally thin, I see no other solution than eating hyperpalatable foods to increase weight. Telling somebody to eat more potatoes isn't going to work, you need to activate the reward system in the brain to promote overeating.
I think mashed potato with lots of butter is never going to promote excess calorie consumption anywhere near as much as chocolate or coke. Except for some individuals with rare disorders obesity just doesn't exist is societies without sugar.
yeah you are
Build a man a fire and he's warm for a day. Set a man on fire and he's warm for the rest of his life.
my recipe for hot chocolate that has helped put weight on my skinny son and sickly father is this:
Melt 1/2 cube butter in saucepan. Add 3 Tbsp of high quality stoneground/raw chocolate and melt together. Add honey to taste (I only use about 1 tsp). Stir thir constantly, and slowly add milk - I don't know how much, because I just keep adding until it's the right thickness. I like it thick, almost like liquid fudge.
I know it's not primal exactly, but w/high quality ingredients, it is very helpful.
I am in Guatemala, where fresh stoneground chocolate is available anywhere and super cheap, and could prob be adapted for reg chocolate...
I think the thing everybody seems to be over looking is that people are genetically different. Maybe the OP is genetically programmed to have low amounts of muscle and fat. Strength training will increase muscle mass but it is unlikely they are going to catch up to somebody who is naturally muscular and who also does weights. Regardless the best shot they have of gaining weight of any sort is to combine highly nutritious animal products like milk and eggs combined with hyperpalatable foods. But like some people are very susceptible to the addicting qualities of tasty foods (like me) some people are completely immune to their addictive properties and may have a very hard time gaining weight no matter what they do.