I would suggest something like the Primal Body, Primal Mind diet. There is very little meat consumption there. It could even be ovo-vegetarian. Most of your calories will be coming from fat and the bulk of your food will be vegetables.

Having said that, yes, I do think you can get adequate nutrition on lots of salads, smoothies, nuts and seeds, and occasional meat and eggs. You really have to watch the Omega 6 with the nuts and seeds though.

Your symptoms are indicative of most likely hypochlorhydria (low gastric acid secretion) and possibly gallbladder congestion. There are many things that can cause low gastric acid (high carb diet, low metabolism, age, etc.) and there are some simple fixes.

Easiest thing (besides chewing very well) to try first is Bragg apple cider vinegar. Do 2 Tbsp in 4 to 8 oz of water and have it prior to meals. It may be something you need to do for a few days to a week before you notice much difference but it is a very natural way to go about it. If this helps eventually you can have a couple tsp in 16 oz water that you will sip throughout the day. I believe after being paleo long enough the problem will correct itself (intolerance of meat & constipation are very common signs of this issue as it heartburn). The other thing you could do would be take betaine hydrochloride (which they get from beets) and take a tablet/capsule during meals. Again eventually the diet should correct the reason for hypochlorhydria. Balancing body chemistry can be slow so don't start to doubt your methods for maybe 3 months. Sooner or later you should not have to use anything to help you tolerate the proteins. http://www.vitacost.com/bragg-apple-cider-vinegar-organic-raw-16-fl-oz

http://www.vitacost.com/solgar-beta-pepsin

The gallbladder releases bile to help us digest fats & oils. It can become congested over time and fail in it's production due mainly to sugar/carb intake. Supplements with beet juice (leaves & bulb) are very good for gallbladder health. They thin the bile so more can be released and better breakdown of fats is achieved. Also coffee enemas achieve this. There is a gallbladder flush you can look into involving apple juice. The symptoms of this issue besides the constipation are intolerance of fatty/greasy food (feeling queezy or turned off), pain in the region of the gallbladder after a meal, burping, etc.

Read this book if you are science minded: http://www.amazon.com/The-Art-Science-Carbohydrate-Living/dp/0983490708/ref=sr_1_3?ie=UTF8&qid=1350052549&sr=8-3&keywords=jeff+volek

Read this one if you are not: http://www.amazon.com/The-Art-Science-Carbohydrate-Performance/dp/0983490716/ref=sr_1_1?ie=UTF8&qid=1350052604&sr=8-1&keywords=jeff+volek

Paleo/low carb diets are sustainable if you understand that we need more fat then protein on a ketogenic diet. Meat consumed in large enough amounts will elicit a glucose spike in the blood due to glycogen. The sustainable way to go is most calories from (good) fats, less from protein (3-4oz meat per meal is enough), very little carbs. But you can still have large amounts of the low carb veggies. Also do research into the omega-3 to omega-6 ratio issues because if your don't eat enough (naturally fed) animal fats and have too many nuts/seeds you will have issues.

Hope this helps.

You definitely need to increase your fats. Try to get around the ratio of 5:1 - Fat : Veg/Meat. The Veg/Meat part should be mainly vegetables.

I think with diet's like Paleo, everyone thinks it's all about meat. No, some meat is fine, but not a whole truck full of it. Good quality fats from grassfed and wild animals will serve you very well. There's a lot of good information and experience over at http://realconstipationremedies.com when it comes to eating more fat to heal constipation ailments. It sounds like the author of the articles is recommending a paleo-style diet to help others. You might want to try and contact that person yourself?

Whatever you do, don't be afraid to lather the fat on your foods!