Article is updated below.

The vast majority of the reasons people go to the doctors are preventable. 25% of Westerners for example, have gut issues. Possibly another 50% is about conditions ranging from depression (1 in 10 Americans take dangerous drugs for it), to painful period, to acne, to asthma, to cancer. In my (non-scientific) estimation, 75% of all conditions that drive people to visit doctors can be prevented if these people were to go Paleo/Primal, and most importantly, if they were grown up with such a diet (most current adult patients can only be made asymptomatic on such a diet, but they can’t fully heal, while kids can). Think how much cheaper a free healthcare government program then it would be. Republicans wouldn’t even make such a fuss about it.

This is how my worldview changed in this past month, after my switch to Paleo:

Of course, having everyone feasting on game, pastured meat, organic & local veggies/fruits, and completely ditching grains & beans is not sustainable for 7 billion people. But this does not negate the above reasoning, it just says that we need to limit our numbers on this planet, so we can live healthy lives. Quality, not quantity.

More information on the leaky gut, that you most probably have without knowing it, here.

UPDATE: How to reset your leptin resistance (a master hormone that also regulates cortisol & insulin), and gain your health back (based on Dr Jack Kruse‘s protocol). It is what I follow myself. On this regimen, if you’re overweight you’ll lose weight, if you’re underweight you’ll gain weight:
Rule 1: Never miss breakfast, eat protein with some fat. Avoid carbs if you can.
Rule 2: No snacking at all, but especially after dinner. Timing is important. Eat breakfast between 6-8 AM, lunch between 12-2 PM, and dinner between 6-8 PM. If your day falls differently, then adjust. Meals need to be spread out to give the liver time to use gluconeogenesis again.
Rule 3: Follow the Paleolithic diet explained below, for life. Learn to eat all kinds of veggies (including rare ones), and get used to eating offal & bone broths.
Rule 4: Supplement with a good multi-vitamin. The most important vitamins are D3 (the recommended value is apparently too low at 400IU, especially if you’re not going out in the sun much), K2 MK-4, Magnesium, and DHA/EPA. Eat fermented foods, or get a multi-probiotic, especially if you have gut issues.
Rule 5: Walk. Lift some weights occasionally. No need for heavy exercise.

Bonus: Meditation, especially for those with cortisol problems.

Update 2: The Paelo/Primal/SCD diet food list. Do not count calories, do not eat processed foods, read labels! And remember, Paleo is a diet to get your health back, weight loss is just a natural outcome out of it only IF you’re overweight.

- Drink enough water. Between 2 and 3 liters a day, depending on sex, age and activity. Water is good for you.

- ALL kinds of eatable vegetation, from green leaves to roots, herbs, spices, tubers, mushrooms, squashes etc. Starchy tubers (e.g. sweet potatoes) must be eaten in moderation or after workouts. The ones that are NOT ALLOWED are: potatoes (at least not with skin on), all wheat/grains/corn/rice, beans/soy — and all of their by-products (always read labels of products you buy). Regarding flours, you can use almond and coconut flour, tapioca as a thickener, but even these must be used rarely. Eating 2 cups of almond flour for a pizza dough becomes unhealthy pretty fast too.

- Meat, fish, eggs, shellfish, game. Offal (especially liver), and home-made bone marrow broths must be eaten regularly. Try to achieve a 2:1 ratio of omega-6 to omega-3 by purchasing pastured meat and wild-caught fish.

- All fruits, in some loose moderation. Berries, avocados, olives are the most-suggested fruits, the rest of fruits must be thought of only as a “dessert”. Commercial fruit juices are not allowed, but rarely you could make your own fruit juice or smoothie. These must include all of the fruit’s pulp, not just the sugary juice.

- IF you can tolerate dairy, you can have goat or sheep hard cheese and home-made probiotic lactose-free goat or sheep kefir/yoghurt. Unless you can perfectly tolerate it, avoid cow dairy (its casein is problematic), except for grass-fed butter/ghee and possibly sour cream. Unless you can trust your local raw goat milk, avoid animal milk altogether (coconut milk is ok, soy milk is not ok, almond milk is so-so). Note: home-made kefir is a super-food, and an opinion on goat/sheep dairy being tolerable.

- Good fats: Coconut oil, olive oil, butter, red palm oil, ghee, tallow, lard, duck fat, a bit of nut butter. Vegetable/seed oils (PUFA) are not allowed. Mostly cook with coconut oil, and use olive oil raw in salads.

- Nuts, except peanuts and cashews. Peanuts are NOT nuts, they’re dried beans (although opinion is divided on cashews)! All the rest of nuts are allowed, unsalted and preferably raw — in moderation (they contain lots of phytates and PUFA, so take it easy with nuts & seeds). Especially take it easy with nut butter and nut flours!

- Seeds (in moderation). Squash/pumpkin, pine, and dried watermelon seeds are very nutritious. Quinoa & amaranth seeds are grain-like, and so they aren’t allowed (they contain saponins), but their green leaves are good to eat.

- Honey. It must be local, raw & unfiltered when eaten out of the jar, but it can be a cheaper kind for cooking. You can also sweeten foods with home-made no-added-sugar fruit jam. You can use pure maple syrup, but only in small quantities. All other sweeteners, including sugar, stevia, agave, and all artificial ones are NOT allowed.

- 99% cocoa dark chocolate, in moderation. Don’t worry, after 4-5 weeks on this diet, you’ll be eating such a bitter chocolate without a problem. Your taste buds will regrow!

- Herbal Tea of your choice, decaf green tea. Avoid alcohol & caffeine (especially beer, it’s loaded with gluten). Decaf Kombuscha is a great fermented green tea, chamomile a great herbal tea, and the Greek Mountain Tea is another great one for health (if you can find it).

- Salt of your choice (especially sea salt). Eat sea veggies once or twice a week too, in order to get more iodine.

- Modern veggies/fruits are aggressively selected, and the earth has lost minerals after thousands of years of agriculture, so they’re often poor nutritionally. Consider supplementing with a multi-vitamin one day, and alternating to a D3+K2+Mg+Ca mix and Krill Oil the next day. If you’re doing a Paleo-keto version of the diet, also consider eating beet greens occasionally, and sea veggies more often than usual.

Special Note: If you are not doing a Paleo-ketogenic diet, you could eat lentils after 6 months on the diet, sparingly, but only after you wash them, soak them in lots of water for 12 hours, and then you thoroughly scrub them among them, using your palms. This technique can get rid off most of the dangerous lectins found on lentils. Also, green bean & pea pods are ok to eat. Here’s a list with the top-10 Paleo foods.