The human genome didn’t undergo any drastic fat-storing mutations around 1990. But the obesity rate has skyrocketed in the past 20 years, reaching almost 36% in 2010. The problem is not with our bodies – physiologically, we’re the same as we always were. The problem is the disjunction between the world we evolved to thrive in and the world we actually have to deal with.
Evolving in a premodern food environment forced our bodies to adapt to an inconsistent food supply. We’re very good at storing fat, because for most of human history, our next meal was a lot further away than a trip to the Quickie Mart. Fat storage allowed us to stock up on food when it was available, and use those reserves during periods of scarcity. A biologically hardwired taste for fat and sweetness directed us to calorie-dense foods when they were available, maximizing our energy intake to prepare for lean times ahead.
Unfortunately for us, our food environment has changed faster than our bodies can keep up. Adapted for food scarcity, we’re confronted with overabundance and the constant struggle to limit our consumption. The foods available in the modern world are also more intensely stimulating than anything our brains evolved to deal with. Most people innately find certain tastes and textures (sweetness, saltiness, crunchiness…) pleasurable; this pleasure is called food reward. Highly processed foods overwhelm our brains with a level of food reward that they simply can’t handle, creating a kind of food addiction and throwing our natural taste for healthy foods completely out of balance. At the same time, these foods lack in nutrition what they provide in calories, creating the paradoxical problem of simultaneous obesity and malnourishment.
The Paleo diet helps many people lose weight because it re-creates the food environment that we evolved for. Some people accomplish this effortlessly. They cut out the “heart healthy whole grains” and the weight seems to melt off faster than they can buy new jeans. But others struggle with their weight even after the switch – and some people initially see great success but then plateau. Putting so much effort into a healthy diet and regular exercise only to see no results can be incredibly discouraging. But whether you’re just starting and frustrated at your lack of progress, or stuck in a plateau after a few months of success, there are many ways to optimize a Paleo diet for healthy, sustainable weight loss.
The Paleo diet rejects an exclusive focus on calories (the “calories in/calories out” hypothesis) as a method of weight loss. First of all, this theory doesn’t distinguish between calories that are nourishing and calories that are harmful: you will lose weight if you eat nothing but 1,200 calories of Doritos every day, but you’ll also develop severe digestive problems and micronutrient deficiencies that do far more damage to your health than the weight loss repairs.
On top of that, even the weight you do lose is unlikely to stay lost. In the absence of industrially processed foods your inflaming digestive system and overstimulating your food reward centers, your body has a natural set point for body fat that it wants to maintain within a few pounds. This is called homeostasis. If you can stick with calorie restriction long enough to lose any significant amount of weight, your metabolism will slow to lower your energy needs, decreasing the number of calories you burn just to maintain your basic body processes. You’ll feel constantly hungry and your body will squeeze every scrap of energy out of the food you do eat. If you overeat enough to create a significant weight gain, your body will do just the opposite, raising your metabolism to burn more calories even while you’re at rest, decreasing your appetite, and using fewer calories from your food. Your body wants to stay at your set point, and it has a series of very effective mechanisms to keep you there.
Paul Jaminet also hypothesizes that your body has an even more important set point for maintaining the health of your lean tissue. Instead of sending signals to your brain through an easily measurable hormone like leptin, lean tissue uses the nervous system, which is harder for scientists to measure but a much more sensitive messenger. If your body isn’t getting the micronutrients it needs, it will try to get more nutrients using the same mechanisms that it uses when you fall too far below your body fat set point: increasing your appetite and extracting more energy from your food. Since your body is trying to maintain both weight and lean tissue mass, a low-calorie diet devoid of adequate nutrients sets you up to fight two biological set points every step of the way – it’s a battle that most people lose.
Luckily, it’s a battle you don’t have to fight. It’s true that weight loss requires you to create an energy deficit by burning more calories than you take in. The problem with deliberate calorie restriction based on a simplistic calories in/calories out model isn’t that calories don’t matter. It’s that this isn’t actually the best way to create a deficit, because it doesn’t account for the different ways you process different foods. Scientists test the calorie content of food using bomb calorimeters, which don’t come close to imitating the complexities of human digestion. A steak and a Pop-Tart might have the same number of calories, but the similarity ends there. This makes focusing on nutrients and food quality an easier and more effective way to achieve the energy deficit necessary for weight loss.
The three macronutrients are protein, carbohydrates, and fat – and while a balance of all three is important, carbohydrate overload is particularly problematic for obesity, especially since it’s closely intertwined with consumption of nutrient-poor processed food products. A diet based on large amounts of refined carbohydrates (especially in the form of overstimulating junk food like chips and cookies) leads to weight gain because it disturbs your natural balance of two important hormones: insulin and leptin.
Insulin’s role in metabolism is to store carbohydrates in your muscles as glycogen, storing fuel for those muscles to use later. But consistently eating more carbohydrates than your body can use leads to a condition called insulin resistance: your muscles have all the glycogen they can hold, so they start fighting back against the insulin trying to force more glycogen into them. Your pancreas produces more insulin in response, but your muscles just fight back harder. Glucose floating around in your bloodstream is dangerous and potentially toxic; with nowhere else to put it, your body stores it as fat.
The insulin resistance provoked by a hyperpalatable high-carbohydrate diet also disrupts another hormone called leptin, which regulates your body’s efforts to maintain homeostasis (staying at its preferred set point). Leptin is produced by body fat: when you gain fat, leptin levels increase, prompting your body to lose weight; when you lose fat, leptin levels decrease, prompting your body to gain weight. The systemic inflammation associated with insulin resistance throws off this natural balance by creating a condition called leptin resistance, where increased fat mass increases leptin production, but your brain never gets the message. Compounding the problem, a nutrient-poor diet based on processed junk food triggers your body’s efforts to maintain lean tissue mass by decreasing the brain’s sensitivity to leptin, increasing your appetite (and thus your nutrient intake). Since your brain never receives the signals to reduce consumption, you keep eating. Your body tries to produce more leptin to increase the strength of the signal – but the only way to do this is to gain fat. This means that your set point effectively increases: you need to gain more fat for the leptin signal to decrease appetite and raise metabolism to reach your brain.
Overstimulation in the form of industrially processed foods compounds this problem, turning it into a vicious cycle. Higher leptin levels seem to decrease food reward as a way of prompting your body to lose weight, but leptin resistance increases food reward, leaving your body even more overwhelmed in the face of hyperpalatable food. The toxins (gluten, seed oils, high fructose corn syrup) in that food also create systemic inflammation, further feeding the cycle of leptin resistance. Meanwhile, you develop all kinds of other metabolic problems that can eventually lead to chronic diseases like diabetes.
Overweight is a sign that your metabolism and leptin/insulin signaling are damaged; rather than starving yourself on a calorie-restricted diet without fixing the hormonal problems underlying weight gain, you need to allow your body to heal and return to a lower body fat set point. Eating a clean, nourishing diet free from industrial toxins and overstimulating processed foods is the first step. While safe starches are a great component of a Paleo diet for metabolically healthy people, they’re less beneficial for someone whose insulin signaling is already damaged. Using fat as your primary fuel source and keeping your carbohydrate intake as low as possible gives your insulin metabolism the rest it needs to heal. This will trigger your body to enter a state called ketosis, using fat, rather than glucose, as a primary fuel source. You will enter ketosis with a daily carbohydrate intake of 50 grams or less, but to truly give your metabolism the healing it needs, keep your carbs as low as possible. Aim to eat around 20-25% of your calories from protein, 75-80% from fat, and 0-5% from carbohydrates, with no fruit or starchy vegetables like potatoes.
Cutting out harmful foods and limiting carbohydrate intake helps to address insulin metabolism problems, but what you do eat matters as much as what you don’t. Since nutrient deficiencies also drive weight gain, make sure to satisfy your body’s micronutrient needs, even if you’re counting calories. Eating 1,500 calories a day and meeting your nutritional requirements will ultimately help more than eating 1,200 calories a day with inadequate micronutrient intake. Eliminating nutritionally bankrupt processed food products will naturally help with this, since replacing 150 calories from a Twinkie with 150 calories from practically anything else will give you a net nutritional gain – on a Paleo diet, you can maximize your nutrients per calorie even further by focusing on all-star vegetables like kale and spinach. You may need to take supplements at first, especially on a low-calorie diet, but eventually a healthy diet should be sufficient to fill your micronutrient needs.
A nutrient-rich ketogenic diet free of food toxins eliminates both of the major problems that tie excessive carbohydrates to obesity: insulin resistance and leptin dysregulation. Since you aren’t metabolizing significant amounts of carbohydrates, your insulin levels stay low, and your body starts to use your food for energy instead of storing it as fat. Freeing your system from the overstimulation and malnutrition associated with toxic junk food removes the root causes of leptin resistance. Eventually your body becomes more insulin and leptin sensitive as your hormone levels balance.
Lower insulin levels and adequate nutrition also make fat much more sating as a fuel source than carbohydrates, since your leptin production is not disrupted. This is why most people on a Paleo diet don’t need to count calories: they naturally feel more sated even after eating less food. The problem with this approach for the severely obese is that someone used to eating 5,000 calories a day might naturally feel hungry for only 4,000 on a fat-heavy diet – but 4,000 calories a day is still far more than most people should take in, regardless of the source. If you have very severe weight and metabolism problems, your hunger signaling might be so damaged that you need an outside measurement of how much food you should eat, at least in the beginning. One dietary option is to start counting calories; tools like Fitday and My Fitness Pal can help estimate the calories in specific foods, and even provide micronutrient estimates. If this sounds impossibly tedious or disordered, you could also just pay much closer attention to portion sizes.
The upshot for weight loss is that even though a calorie deficit is the only way to lose weight, narrow-mindedly counting calories while ignoring macronutrients and food quality will only produce transient weight loss: eventually, your body will find a way to get back to its set point. Changing the body fat set point and eating enough nutrients to maintain your lean tissue are the keys to long-term weight loss – and a low-carb Paleo diet without inflammatory toxins like gluten and seed oils can help. Some people can effortlessly lower their calorie intake to healthy levels just by switching from a sugar-burning to a fat-burning metabolism, but the very overweight might also need to track calorie to restore healthy metabolic function.
A ketogenic version of a basic Paleo diet can be modified for weight loss the same way it can be modified for IBS, GERD, Diabetes, or any other medical need. Before you start experimenting, make sure you really do have the fundamentals dialed in – if you struggle with constantly cheating, committing to a Whole30 might help you break out of your old eating habits for good. But if you’re following a solid Paleo diet and still can’t make progress, various tweaks and modifications can optimize a generally good diet for your specific circumstances.
Nuts and seeds are problematic for weight loss for a number of reasons. They’re high in calories and very easy to overeat, so if you’re struggling with portion control or caloric intake, they’re a good food to avoid. Nuts and seeds also have high levels of harmful polyunsaturated fatty acids (PUFAs), and poor ratios of omega-6 to omega-3. PUFAs are essential to health in small amounts, but eating too much of them contributes to harmful oxidative stress and inflammation, which is especially bad for people with metabolic problems because inflammation is a major cause of leptin resistance.
Cutting out nuts also eliminates another food category that anyone trying to lose weight should avoid: “Paleo-ified” versions of your favorite junk foods and desserts. These often include “crusts” or “breading” made from nuts – but just because they’re technically Paleo, doesn’t mean they’re good for you. Paleo pancakes sound tempting, but they’re incredibly high in calories (as a replacement for flour, the recipe uses almond meal), and more importantly, they keep you in the wrong mindset. When you’re constantly trying to re-create the food culture of the standard American diet, you start to see Paleo as a set of unfortunate restrictions that you have to work around to keep enjoying your food, instead of a delicious way of nourishing your body. If you never make the psychological switch from junk food to real food, you’ll always feel deprived on a healthy diet. And if you’re constantly feeling deprived – especially if you’re not making progress – eventually you’ll give up. It sounds harsh, but the easiest way to transition to Paleo in the long run is to rip off the band-aid and recreate your relationship with food, rather than going through the motions of your old lifestyle.
Another strategy is intermittent fasting. Intermittent fasting magnifies several of the benefits of carbohydrate restriction: for example, it lowers insulin, prompting your metabolism to use stored body fat for fuel. Since you aren’t taking in any calories during a fast, your body runs entirely on the stored fat. As icing on the fat-burning cake, fasting also raises the levels of several other fat-burning hormones like growth hormone and adrenalin. Like a low-carb diet, intermittent fasting also lowers your calorie intake without forcing you to think about calories: you might eat a slightly larger meal to break your fast, but if you IF for 24 hours you’re hardly likely to eat an entire extra day’s worth of food when you break the fast. As with calorie restriction, however, make sure that intermittent fasting doesn’t lead to any micronutrient deficiencies.
If you’ve been stuck in a plateau after a period of successful weight loss, you may need to briefly change your eating pattern so that your body doesn’t start storing fat as a response to the perceived scarcity of calories or carbohydrates. Many people find that after initial success in healing their metabolism with very low carbohydrate dieting, they achieve their long-term goals by adding small amounts of safe starches back into their diet – a report that the authors of the Perfect Health Diet confirm. Another alternative is calorie cycling. As your body gets used to eating fewer calories, your metabolism slows to more efficiently use the lower amount of energy it’s now getting. A higher calorie intake one day a week can help keep your metabolic rate high, actually helping your weight loss instead of setting it back.
Exercise should go without saying. It’s an integral piece of the insulin sensitivity puzzle: if you regularly use up your muscles’ glycogen reserves, your body uses the glucose you do ingest to replace them, instead of storing it as fat. This is why carbohydrates are such an important fuel for serious athletes, but you don’t need to be a powerlifter or a marathon runner to get started. All kinds of exercise can fit into a Paleo diet – just don’t look at it as primarily a way to burn extra calories. Trying to lose weight by forcing yourself through hours on the treadmill every week is the exercise equivalent of calorie restrictive dieting: intensely unpleasant and largely ineffective.
Instead, find something you enjoy. Even regular walking can improve your insulin sensitivity. Swimming can be a great option if you’re overweight because it puts very little stress on your joints, no matter how heavy you are. Biking is not only low impact, but useful: take a spin down to the grocery store to pick up some dinner and notice how much less appealing that 2-liter Coke looks when you’re faced with the prospect of lugging it all the way home under your own steam.
As you develop exercise habits that fit your Paleo lifestyle, you might find more intense exercise useful (or even necessary) to keep making progress in your weight loss. High intensity interval training (HIIT) like tabata sprints is a great weight loss exercise because it burns fat much more effectively than steady-state cardio, but the best exercise for any purpose is the one you enjoy doing, and the one you can stick with in the long run.
Since inflammation is such a major contributing factor to leptin resistance, any change in your diet or lifestyle that reduces inflammation can only help. Toxins of all kinds can be dangerously inflammatory: limit your exposure to environmental toxins like chemical fumes and BPA. If you can afford it, buy organic meat and produce to reduce your consumption of pesticides, antibiotics, growth hormones, and the other harmful chemicals in the conventional food supply. If you buy any processed meats (like bacon or beef jerky), make sure to read the labels carefully – many processed meat products contain sugar or chemical additives, and jerky is often made with soy sauce, which contains gluten. Stress (especially chronic stress) and sleep deprivation produce inflammation by raising your levels of cortisol; do what you can to keep yourself out of the sleep-stress cycle.
Successful weight loss isn’t about counting calories in your low-carb tortillas, or “earning” every indulgence with an hour of sweating it out on the treadmill. Trying to starve your body into submission without addressing your underlying metabolic problems and nutritional needs is ineffective and unnecessarily painful. The key to lasting weight loss is repairing the damage to your metabolism and hormonal systems from the toxic modern food environment – a ketogenic Paleo diet gives your body the chance to heal itself, creating a solid foundation for your long-term health, not just a temporary change in your belt size.
P.S. Be sure to check out the Paleo Recipe Book. It’s a cookbook I’ve created to help you cook the best food for your health. It contains over 370 Paleo recipes and covers absolutely everything you’ll ever need.