If I include a lot of fruit and nuts, make an attempt to eat until I'm completely full, and sit on my ass all day I can get a bit of a pudge going. Other than that, no.

The Paleo Diet is a way of eating for life not a weight loss mechanism per se.

Avoid vegetable oils and sugar and you will be healthier. Eat only whole foods and avoid grains and you will be healthier yet.

There are 1000s of ways to eat Paleo and some can cause weight gain. However if you are looking to lose weight the Paleo way of eating can be very effective.

Yes one can........

If I eat too many carbs, I can easily gain weight on Paleo.

Paleo is a "diet" in that it's a 'way of eating', not necessarily "diet" as 'a way to lose weight'. The weight loss aspect is magnified beyond what I think it should be. Can you pig out on fatty meat, nuts, fruit, and gain weight? Of course you can! The Paleo camp is made up of people who want to be more healthy, get lean and cut, heal health issues (digestion and the like), perform better athletically, and lose weight/attack their obesity issues. The Lose Weight crowd often seems to see Paleo as the next miracle diet to "make them skinny". It's not. Eat too much, eat the wrong things, don't move your body, and hell yeah you can gain weight.

As a hypothyroid (an instant fat maker issue), I find I have to be careful of not only what I eat but the proportions of macro nutrients. Too much simple carb intake piles the weight on like crazy. I fall into the low fat trap easily because that message is everywhere so it's hard to get it out of mind. When it gets in my brain, I unconsciously veer from fats and toward carbs because I'm hungry all the time. I must be very conscious of keeping these two things balanced. To feel my best and lose (like presently) or maintain a good weight, eating the paleo way is best; it keeps me focused on the true good stuff and staying balanced with no counting.

Yes, you can. I've been skinny and lean my whole life, but I gained 10 lbs eating high calorie paleo. Granted I was intentionally eating as much as I could. Not all of it is muscle (I am a girl), but a good deal of it is, and I got a lot stronger.

I have two cats that have been 'paleo' (they eat 100% raw animals - zero carb) since I got them as little kittens 6 and 4 years ago. They are much more muscular and solid (with very tight skin) than most cats I touch, however they do have a little 'extra' body fat in the usual belly area, and they can easily put on more fat if they eat to excess and will lose it if I diet them down. A fatty (high-cal) diet noticeably packs weight on them. The younger cat I have to watch like a hawk (and feed lean cuts) in order to keep him from getting chubby (he is a thief and a compulsive overeater). If he was an outdoor cat and could hunt and eat all he wanted, I bet he'd be a fatass. Of course, they are spayed and neutered, and it might be that they would stay lean more easily if they were intact.

Calories count for something.

Yes you can gain body fat eating paleo.

To gain body fat all one has to do is eat more calories than your body requires to maintain its current weight, while having no stimulus for your muscles to grow. If you are providing your muscles a stimulus to grow (usually achieved by lifting weights) and eat a surplus of calories than some of those calories will probably go to building and repairing those muscles.

No diet can prevent you from gaining weight. If you go over your caloric needs, your body will store the excess as fat. Now determining what the threshold is, is another story.

As always, it comes down to listening to your body and measuring yourself (not just the weight scale, but body fat %, waist, chest, arm, etc circumference, paint size) if you are having problems losing extra weight.

If you think your diet is good, look at your sleep patterns, stress levels, etc.

If you still have problems after that I would recommend recording what you in eat in a food log like FitDay, to have a more unbiased approach. Some people eat a lot more than they think. So you could be overdoing the nuts, or cream. I would try to find the bottleneck to my weight loss and narrow in from there.

Of course, exercise can help too.

It's definitely possible to gain weight if you eat too much calorie-dense foods, even from paleo sources (as I've demonstrated to myself when I've let myself backslide, portion-wise).

Paying attention to cues from my body, such as noticing when I initially started to feel sated and stopping eating at that point, helps me to counter this but for me a lot of my results come from actively working against my pre-paleo habits (especially that "clean your plate" thing).

I've not done any calorie-counting though (either before or after going paleo), feeling more comfortable sticking to a general low-carb diet for my on-going weightloss (although I've found that even fruit can make for a weight-increasing binge). Personally, I've had days where my single meal of the day consisted of a pound of steak with half a stick of butter and couple of heaping tablespoons of cream cheese, feeling full afterwards (ok, no surprise there), and still lost weight.

I am heavy and have stayed heavy and even gained weight (when not sleeping/stressing too) on paleo at times, but unless I add sugar it has never been much.

don't worry, just don't act like a food addict.

I think I may be gaining fat on Paleo, but I am hungry all the time. Real hunger. Am I just supposed to ignore the hunger pangs?