The following is from crossfitkarla’s Tumblr but because she answered this as a question from someone, I could not properly reblog, so here it is copied and pasted with credit:

This is from traindirtyeatclean.tumblr.com and is the best description for paleo:

• The Paleo Diet

  Most frequent question I hear:

  Angie I want to lose weight, what should I eat?

  My answer: Paleo

  Second most frequent question I hear:

  What is Paleo?

  Okay, so before I get into what Paleo is, and more important, why I eat Paleo, I’m going to tell you that everything you were ever taught about food by the USDA, it’s all wrong. So I just hope you are ready to change the way you’ve looked at food for your entire life. Because that is what happened to me when I discovered Paleo.

  But this is great news, because you are going to be free you from all of the crazy dieting you have ever put yourself through. You can finally stop meticulously counting carbs, calories and fat, for the rest of your life, from this point on. As long as you stick to Paleo foods, and eat them in reasonable amounts.

  I’m going to spare you the scientific background on Paleo and nutrition, I’ll get into that in another post in the future. I don’t want to overwhelm you.. my main goal in this post is to really just open your eyes to the misconceptions we have about food today, and why I really believe that Paleo is the most optimal and perfect diet, for you, me, and every other living human.

  

  Here is the Paleo Food Pyramid. Paleo is also known as the “Caveman Diet” because it’s how our ancensors ate before agriculture existed. Basically, we can eat things that can be “hunted” and “gathered”. If you haven’t noticed we are missing a few food groups entirely that you’re accustomed to seeing from the USDA Food Pyramid. (Dairy, grains, sweets, oils, fats.)

  First look at all the great foods you can enjoy on Paleo:

  • Lean Meats
  • Fish
  • Eggs
  • Vegetables
  • Fruits
  • Nuts
  • Seeds

  As Well as:

  • Healthy Oils (Olive, Coconut, Flaxseed, Macadamia, etc.)
  • Nut Butters (Almond butter, cashew butter, etc.)
  • Spices
  • Almond and Coconut Milk
  • Water, Tea, and Black Coffee

  And now, foods that are to be avoided COMPLETELY when eating Paleo

  • Grains (There is no eating of grains, even whole grains. That means no bread, pasta, cereal, rice, quinoa, oatmeal, wheat, granola, corn, pastries, chips, no gluten free breads either. Etc.)
  • Dairy (No milk, cheese, yogurt, butter, etc.)
  • Legumes (No beans, peanuts, chick peas, or hummus)
  • Soy Products
  • Alcohol
  • Sugar and Artificial Sweeteners

  I know- all the same thoughts that are going through your head right now, were going through my head when I first learned of Paleo. “How will I get fiber without grains? And I need carbohydrates to survive.” And “No milk or yogurt? How am I going to get my calcium? ” I’ll get MORE into that in a future post. This post is meant to give you a slight understanding of Paleo so you can get started. Like I said, I don’t wanna overwhelm you. I know you’re probably already having a panic attack because I just told you that you shouldn’t eat bread or sugar ever again in your life. hehe jk.

  

  Next time you are people watching. Take notice of how many fit, happy, healthy, energetic looking humans you see. Versus, how many sick, tired, overweight people you see. I’ll put money on it that you see a lot more of the tired and overweight group. Thats the world we are living in today. Despite all the doctors we have and all the advancements we have in the medical field today… the rates of obesity, heart disease, diabetes, and cancers is not getting any better, it’s getting worst every single day. So what do our “doctors” do? They prescribe these sick people with drugs, whether it be for high blood pressure, cholesterol, diabetes, whatever. The solution to good health is not in popping that pill, it’s not in medication or pharmecutical drugs, it’s not in the latest fad diet. The solution is the food we are choosing to put in our mouths today, and everyday for the rest of our lives. I’m a firm believer that food is medicine. Food is the solution to all of these problems we are dealing with today. Food can reverse disease, it can heal, it can get you fit, strong, feeling younger, more energized, even happier.

  

   The foundation of Paleo is looking at where we are now and asking ourselves, how did we get here. Paleo is going back to our ancestors. Before the obesity and diabetes epidemics. Before cavities. Before agriculture, fast food, and processed foods. And back to whole, fresh, nutritionally dense foods. Back to the foods we were designed to eat that will keep our bodies in optimal health.

  I know a lot of people’s main goal is to lose weight. But as you begin losing weight, I guarantee your goal will change from, “I want to be skinny” into “I want to be healthy”. So right now, I’m going to tell you what your want to hear, you wanna hear how Paleo is gonna make you lose weight. (You’ll be super healthy too, because that’s one of the great side affects of eating Paleo.)  Humans have adapted to eating the majority of modern foods like grains, sugar, processed vegetable oils, and other bad stuff. We need to go back to our roots of fresh, natural foods like meat, vegetables and fruit. Which are all foods that are nutrient dense, with naturally occurring vitamins and minerals, over foods that have more calories but less nutrition.

  

  This is a great description of Paleo from http://whole9life.com/
  

  It’s not a low calorie “diet” — I eat as much as I need to maintain strength, energy and a healthy weight. In fact, my diet is probably much higher in fat than you’d imagine. Fat isn’t the enemy — it’s a great energy source when it comes from high quality foods like avocado, coconut and nuts. And I’m not trying to do a “low carb” thing, but since I’m eating vegetables and fruits instead of bread, cereal and pasta, it just happens to work out that way.

  Eating like this is good for maintaining a healthy metabolism, and reducing inflammation within the body. It’s been doing great things for my energy levels, body composition and performance in the gym. It also helps to minimize my risk for a whole host of lifestyle diseases and conditions, like diabetes, heart attack and stroke.

  You now have a general understanding of my eating habits and why I choose to eat this way. I have only been eating Paleo for a few months and already see changes in my body that I have never seen before. My performance in the gym is the best it’s ever been, my lean muscle mass in higher, my body fat percentage continues to decrease, I don’t get sick, I always have energy, I’m stronger, fitter, and feel younger than I have ever felt. This is something I will stick to for life. The food choices are endless and I guarantee there are Paleo foods you’ve never even heard of or tried. Hopefully if you don’t chose to follow strict Paleo, you can at least incorporate this information into your life.

  I will leave you guys today with an awesome list of Paleo vs Non Paleo Foods.

  http://desertcrossfit.typepad.com/Paleo_Food_List.pdf

  I also find cookingcaveman  an invaluable tool for understanding Paleo and gathering simple, great tasting recipes.  #crossfitcandy