Understanding Paleo, Ketogenic, Intermittent Fasting, Whole30, Mediterranean, Carb Cycling, and Plant-Based Diets

Gluten-Free. Paleo. Weight Watchers. Whole30. Ketogenic. DASH. The list of diets, and their various rules and restrictions, is endless. One person swears by fasting. Another finds success slashing carbs. Others fill up their dinner plates with only plants. Regardless of the dieting method, of the millions of Americans who embark on an eating plan each year, many do so to lose weight. Other health measures such as improved energy levels and mental clarity are also motivating factors. Since no time is more popular for going on a diet than the New Year, here's how some of today's most buzzy diets stack up, plus how to tell if any are right for you.


Nuts and Bolts: When it comes to #trendingdiets, this is a big one. People who fuel their bodies on this ancestral diet eschew agricultural-era foods such as grains, legumes, and dairy. Instead, they focus their eating efforts on items such as meat, fish, eggs, fruits, nuts, seeds, and veggies that were available to our hunter-gather ancestors. The diet also deters you from drinking alcohol. Fat loss, more energy, clearer skin, less bloating, fewer sugar cravings, and a drop in disease-provoking inflammation are among the advertised benefits of eating the caveman way.

Pros: If anything, the Paleo diet is great at weeding out processed foods from your
diet, because so many of those contain refined grains or added sugars--two big
Paleo no-nos. So it's bound to increase your protein intake, which can help silence hunger to squash overeating and build metabolism-boosting lean body mass. It's also not necessarily a low-carb diet, so you can sidestep the fatigue, headaches, and other side effects of carb-stingy eating plans. Some studies show that a Paleolithic-type diet can improve blood sugar control and blood lipid numbers, which may confer protection against maladies such as diabetes and heart disease.

Cons: Eliminating dairy, grains, and legumes can leave you short-changed on certain vitamins, minerals, and antioxidants, so you'll need to make sure they are coming from Paleo-approved sources. Paleo demonizes whole grains, even though research links them to better health outcomes and trimmer waistlines. Some use the Paleo philosophy as an excuse to eat too much meat and too few plant-based foods. If you follow recommendations from the throwback diet to eat grass-fed meats, wild seafood, and organic veggies, the diet will require a much bigger food budget. And anytime food groups are eliminated, eating during social occasions can be problematic.

Make it Better: Don't just put slabs of meat on your plate. Take Paleo as an opportunity to experiment with a variety of new allowed foods from different food groups. Arctic char and celery root, anyone? Search online or invest in some Paleo cookbooks for recipe inspiration so your meals stay more exciting than chicken breast with steamed broccoli. It can be helpful to speak with a dietitian to make sure you're getting your daily quota of calcium, vitamin D, and other essential nutrients. If you work out regularly, be sure to eat plenty of fruits and starchy veggies such as potatoes so you get enough carbs to power your stride. If you prefer to baby-step your way into Paleo, you can try slashing dairy from your diet the first week, bidding adieu to refined grains during week two, then skipping all grains the next week, and so on until you're following a hardened Paleo diet.

See Also The Benefits of Going Paleo


Nuts and Bolts: The ketogenic or "keto" diet is all about one thing: fat. Keto dieters obtain 70-80 percent of their calories from this macro while eating very few carbohydrates (generally fewer than 50 grams a day, or no more than 5 percent of total calories) and only moderate amounts of protein (no more than 15-20 percent of total calories). Why the fat payload? Proponents say the carbohydrate and protein restriction will move your body into ketosis, prompting it to access ketones generated from stored fat as its primary fuel source instead of carbs, leading to a trimmer waistline, fewer energy crashes, and better protection against certain maladies, including diabetes. So you can go ahead and splurge on cheese, avocados, coconut oil, egg yolks, fatty nuts like cashews, olive oil, and fat-dense meats such as sardines and bacon with the goal of becoming a better butter burner.

Pros: Sugar is the diet's enemy, so it can be the catalyst some people need to break their relationship with the sweet stuff. And going low-carb could also help you eat less overall, because fat is generally more satiating, which can be one mechanism behind the diet's war on body fat. Ketone bodies themselves may have a direct hunger-reducing effect. Some beneficial metabolic changes that come with the ketogenic diet, at least in the short term, can include less insulin resistance and lower blood triglyceride numbers.

Cons: Keto diets can definitely help people shed those stubborn pounds in the short term, but long-term results in terms of fat loss and overall health have still not been proven. (Most studies on high-fat eating have been performed on rodents.) The fat-first diet is pretty restricting, so you won't be nibbling too much on some of the most nutrient-dense foods in the supermarket, including beans, berries, whole grains, and sweeter veggies such as peas and carrots. In fact, because you are restricting so much, adherence to the diet long-term can be a challenge, especially when you limit otherwise enjoyable foods. Without a careful approach to keto, you risk fiber and micronutrient deficiencies. While giving up processed foods is a smart move, eating more cheese, steak, butter, lard, and bacon can up your saturated fat intake, which is still a concern for heart health. A 2018 study in the journal Lancet found that people on a low-carb diet where calories from carbs were replaced with animal fat and animal protein raised their risk of early death. The loathed so-called "keto flu," which includes fatigue, nausea, and brain fog, happens to many people during the first few weeks on the diet, when the body is adapting to the new normal. And performance during higher-intensity bouts of exercise can be compromised with a lack of carbohydrate energy stores. Too much protein can throw you out of ketosis, but it can also make it harder to put on lean body mass.

Make it Better: To avoid nutritional deficiencies, make sure you're not eating the same rotation of foods. Include a daily variety of the allowed meats, fish, non-starchy vegetables, dairy, nuts, and seeds. A fiber supplement might be needed to keep your bowels and microbiome in working order. It's possible to modify the diet to emphasize fatty foods low in saturated fat or from plant sources such as olive oil, avocado, nuts, seeds, and fatty fish. For a more sustainable long-term approach to eating, when weight loss or other health goals are achieved on the keto diet, one may follow the diet for a few days a week or a couple weeks each month, interchanged with other days, allowing a higher carbohydrate and protein intake.

See Also What Is the Keto Diet?

Intermittent Fasting

People gravitate toward intermittent fasting because there are no off-limit foods--just limits on how much you can eat at certain points.
People gravitate toward intermittent fasting because there are no off-limit foods--just limits on how much you can eat at certain points.

Nuts and Bolts: Not a diet in the classic sense, intermittent fasting (IF) is defined as cycling your diet between periods of restricted eating and periods of eating as much as you normally do. There are several different patterns of intermittent fasting, but a few of the more popular include the 16/8 method, where you fast for 16 hours and eat only during an eight-hour period; the 5:2 diet, where you eat no more than 25 percent of your normal calorie intake two days out of the week; and the eat-stop-eat method, which involves a full-blown 24-hour fast once or twice per week. The theory is that when your body is in a fasted state, it's more likely to alter metabolism to improve blood sugar numbers and pull more energy from your fat stores, leading to a trim-down effect. And since in theory you're likely to nosh on fewer calories during the course of a week, this itself could help in the battle of the bulge.

Pros: IF has become a go-to method for getting lean fairly quickly. Indeed, there is some good research that this flexible style of eating can be just as effective in spurring weight loss as more drastic everyday calorie restriction. A 2018 study published in the Journal of Nutritional Science found that simply moving breakfast and dinner three hours closer together led to drops in body fat in subjects despite no change in overall caloric intake. People also gravitate toward IF because, unlike other diets, there are no off-limit foods--just limits on how much you can eat at certain points. And it can help people get in better touch with their true feelings of hunger and fullness as well as put the brakes on nighttime snacking.

Cons: Studies with large sample sizes or dealing with the long-term weight-loss benefits of IF are still lacking. One investigation was hindered by a large number of participants who failed to follow the diet until the studies ended. So IF may suffer from what befalls many diets--high dropout rates. Side-effects such as raging hunger, brain fog, and irritability during fasting can be too much for some people to work through. Because there isn't much focus placed on what you eat, some people might be tempted to reward a fast-well-done by eating junk food.

People gravitate toward intermittent fasting because there are no off-limit foods--just limits on how much you can eat at certain points.

Make it Better: Consider easing into IF by starting with a beginner's 12:12 method, where you're fasting for 12 hours per day and eating within a 12-hour window. From here, you can work your way into more challenging fasts. Make your calories count during fast and feast periods by focusing your eating efforts on nutrient-dense, whole foods. Items rich in fiber or protein like legumes and Greek yogurt can help tame the hunger monster during times of calorie restriction. A food journal can help make sure you're not overeating on fasting days. And consider exercising during your eating window so you have more pep in your step.


Nuts and Bolts: Much-buzzed Whole30 markets itself as a method to reset your diet, give your digestive system a break, and help you forge a new relationship with food. With this elimination-style diet, you're told to cut out items that are known to upset some tummies or are generally unhealthy--all processed or packaged food, natural and artificial sugars, alcohol, grains, beans, legumes, soy, and dairy are off the menu for 30 days straight. Even packaged foods like Paleo pancake mix with Whole30-approved ingredients are ziscouraged. Meat, seafood, eggs, vegetables, nuts, oils, and fruits are allowed. The goal is to rewire your brain to crave whole foods and to weed out items that aren't settling well with you. After 30 days, you can slowly add food groups such as beans and whole grains back into your diet as a method of testing for food sensitivities.

Pros: If you're looking for a fairly drastic dietary kickstart, especially post-holiday season, this could be for you. Keep in mind that it was designed for only 30 days, so after this time you can ease your restrictions and modify the diet to be sustainable long-term. Many people will notice their pants fit a bit looser, which should be expected when eating less overall. The diet can also be helpful for identifying any food intolerances such as lactose that could be behind symptoms like bloating. And some people praise the diet for helping them kick their sugar lust and practice mindful eating.

Cons: It's a labor-intensive process requiring label reading (remember, no honey in your jerky), lots of meal planning, and more creativity in the kitchen to sidestep food boredom when faced with fewer cooking options. (Yes, you can get fed up with avocado.) Access to only Whole30-compliant foods when traveling or eating out can be a challenge. Vegetarians will struggle to eat enough protein. After any slip-up, even if it's just a piece of bread getting in the way, you're encouraged to start over--grrr. Expect some side effects such as fatigue and cravings that come with reducing calories and carbs. There can be a tendency to gorge on "forbidden" foods post-Whole30, which can quickly undo any benefits gained from the previous month. And any diets that preach restriction risk leading to certain nutritional deficiencies and disordered eating patterns.

Make it Better: Whole30-focused cookbooks can help keep you on track by providing cooking inspiration with allowed foods. Seeking the advice of a dietitian is a smart move to make sure you're getting all the nutrients such as calcium your body needs in absence of certain food groups. When the clock strikes midnight, slowly add in the healthier foods you've been steering clear of such as whole grains, lentils, and yogurt so you get a better sense of how you respond to them. Despite what the diet may lead you to believe, most people should be eating more of items like beans and whole grains, not less.


Nuts and Bolts: Among the plethora of diet regimens, the Mediterranean diet has garnered the most wide-spread praise among health professionals. Essentially, the diet is about implementing the components characterizing the traditional cooking style of countries bordering the Mediterranean Sea. Namely, eating plenty of fruits, vegetables, herbs, whole grains, olive oil, fish, poultry, nuts, and legumes, while reigning in your intake of red meat, refined grains, and highly processed packaged foods that are typical of the standard American diet. There is little focus placed on counting calories--diet quality matters most.

Pros: Research suggests that the benefits of following a Mediterranean-style eating pattern are far-reaching: better heart health, less risk of depression, improved vision and bone health, weight loss, and lower rates of cognitive decline, to name just a few. The nutrient-dense whole food focus of the Mediterranean diet is why it can do a body good. And because it doesn't call for any serious diet restrictions (yes, you can eat bread, especially if dipped in olive oil), the flexible diet is one of the most sustainable long-term.

Cons: Because you're for the most part on your own to decide what to eat and how much to eat, dieters who benefit from more structure or require more immediate results may stumble with the Mediterranean diet. And it may trim your wallet as well as your waistline. A study concluded that subjects who adhered most closely to the Mediterranean diet spent more on food each day than those who ate mostly a "Western" diet.

Research suggests that following the benefits of following a Mediterranean-style eating pattern are far-reaching: better heart health, weight loss, and lower cognitive decline.

Make it Better: Strive for including one to two servings of veggies at every meal, replace refined grains in your diet with their whole version, snack on fruits and nuts, and try to nosh on fish at least twice a week, with a focus on omega-3 rich varieties such as salmon, trout, and sardines. To reduce the pain at the checkout, scoop up Mediterranean staples, including beans, nuts, and whole-grains from bulk bins. Local, in-season fruits and vegetables from farmers' markets can often be had for bargain prices. Though made up mostly of healthy fats, items like nuts and olive oil still pack a calorie punch, so portion control is a must--another thing people in Mediterranean countries are noted for. And try to embrace the social component of eating as they do in the Mediterranean by sharing meals with family and friends more often.

Carb Cycling

Nuts and Bolts: The gist of this diet is that you alter your carbohydrate intake throughout the week, month, or year. There are usually high-carb, medium-carb, and low-carb days cycled throughout a period of time. The rationale behind carb cycling is that when your body receives limited carbs, it relies on fat as its primary fuel source, which can be helpful for weight management, and also helps your body to become more sensitive to insulin to better utilize carbs when they are reintroduced. Figuring out how many grams of carbs to eat each day is an individual choice, but as a general guideline, many people consume about 60 percent of their calories from carbs (or roughly 1,000 calories for a 1,800 calorie diet) on high-carb days. On low-carbohydrate days, this can drop to 5-10 percent of calories. A medium-carb day during the week could see you consuming about 40 percent of your calories from carbs, but some people just stick to a low- and high-carb cycle.

Pros: Many people find that moving between periods of different carb intake is less onerous than sustaining more prolonged periods of low-carb munching. It's easier to march through a couple of low-carb days if you know that a bowl of pasta is on the horizon. "Refeeding" means you don't suffer the consequences of long-term carbohydrate deprivation, making carb cycling a good middle ground.

Cons: Here's the challenge for most people: The cycling period, as well as the amount and the type of carbohydrate, is not defined, so you have to try different types of cycling before figuring out what works for your goals. The planning and tracking to be successful means the diet can be mentally draining. And for some people, obsessing about counting calories and macros can spiral into an unhealthy relationship with food. Though some studies allude to the weight-loss benefits of a low-carbohydrate lifestyle, relatively few delve into the concept of swinging between carb intake, so much of the data out there remains anecdotal.

Make it Better: Whether high or low, make sure the majority of your carbs are coming from wholesome sources such as whole grains, fruits, and vegetables. High-carb days shouldn't be filled with muffins and French fries. When trimming the calories you get from carbs, eat enough quality proteins and fats to make sure your body is getting the nutrition it needs. But remember that when carbs go high again, you'll need to scale back your protein and/or fat intake to compensate for the shift in calories. On days when you're crushing it at the gym, aim to consume more carbohydrates, which are the main source of energy for hard efforts. Save low-carb days for desk jockey days or times when training is less intense.


There's evidence that a veg-heavy diet makes it easier to trim the waistline compared to serving up a meat-heavy menu.
There's evidence that a veg-heavy diet makes it easier to trim the waistline compared to serving up a meat-heavy menu.

Nuts and Bolts: Not a diet per se, plant-based eating stresses that your diet is centered around foods grown in soil, namely vegetables, fruits, whole grains, legumes, nuts, and seeds. You can do all this and still allow for meats and dairy in your diet, making it more flexible than vegetarian and vegan diets. So committing to a plant-based diet can mean committing to eating several meatless meals and snacks throughout the week, with some dairy and meat sneaking in there from time to time.

Pros: Research is piling up that there is longevity power in plants. Case in point: A study in the Journal of Nutrition found that a healthy plant-based diet is associated with less risk in all-cause mortality. Eating more plants makes it easier to load up on health-hiking fiber, vitamins, minerals, and anti-oxidants. There is also evidence that adopting a veg-heavy diet makes it easier to trim the waistline compared to serving up a meat-heavy menu. And it's a healthy diet for Mother Nature, too, as data shows that eating more plants and less meat can help in the battle against global warming.

Cons: Depending on how plant-centric your diet is, you'll need to make sure to get enough of the nutrition readily found in animal-based foods, such as protein and vitamin B12. It's surprisingly easy to eat a very unhealthy diet even when cutting out animal products. Some people will simply swap out the meat and dairy in their diets with hyper-processed packaged foods full of refined grains, sugar, and unhealthy fats--definitely not a nutritional upgrade.

There's evidence that a veg-heavy diet makes it easier to trim the waistline compared to serving up a meat-heavy menu.

Make it Better: If you've been a hardcore carnivore, consider easing into a plant-based diet by setting small goals. This can be as simple as a couple of meat-free meals each week and working up from there. To keep your palate excited and to make sure nutrition needs are being met, include a variety of plant foods in your menu. Experiment with items such as tempeh and hemp seeds to help nail your protein quota. For plant foods at their nutrition and flavor peak, aim to get more of them from a local farmers' market.