A Guide to the Optimal Diet

Post written by Leo Babauta.

What’s healthy and what’s not — it’s one of the most confusing questions in our lives.

One of the problems is that there are so many different approaches to healthy eating — a dozen different diets advocating often extreme approaches. Should you eat all vegetables, all meat, no grains, all juice, no dairy, lots of dairy, low fat, high fat? It can be too much to sort through.

Another of the problems is that there are so many studies out there, new ones every day, and they can often seem to contradict each other. It’s enough to make most people just give up on paying attention to the research.

In this guide, I will attempt to sort through the mass of contradicting diets and research, and simplify things a bit. I do my best to rely on the mountains of research I’ve read in the last seven years, but often also rely on my own experiences and experiments as I’ve tried to simplify health advice down to the essentials.

It’s a fairly long guide, because I’m covering a lot of topics, but I hope it’ll be useful to those who have been confused as to what they should be eating, and what to avoid, how often, and how to put it all together into an optimal diet.

Short version: If you want to just get the key points, head to the bottom section, “Putting It All Together”.

Sorting Through Different Diets

Every week, it seems like, there’s a new fad diet. I’ve seen diets like the Grapefruit Diet, the Cookie Diet, various juice fasts, and diets that celebrities have used. I’ve personally tried a bunch of them myself, from Atkins to Paleo to the South Beach Diet to the Flat Belly Diet to the Slow Carb Diet to Mediterranean and Okinawan diets to low fat to vegetarian and vegan diets.

Phew!

I’m going to briefly comment on some of the main ones, and then share what I’ve learned in a nutshell from my various experiments.

• Low Carb – There are a variety of diets that fall into the low-carb range, including a couple below, as well as Atkins, South Beach, the Ketogenic Diet and more. The theory behind it all has to do with insulin and how the body processes carbohydrates, and a state called ketogenesis that the body goes into when you deprive it of carbs. And while there is some scientific basis behind it, I’ve found the diets to be too restrictive and extreme. It’s hard to stick with the diet for long, though some people seem to enjoy it more than others. I’ve found that eliminating carbs can be good for the short term, but isn’t really necessary for long-term health or weight loss. It can be done in other ways.
• Slow Carb – This is Tim Ferriss’ version of the low-carb diet, and it’s not bad. He allows a few more carbs than the low-carb diet, especially of the low GI variety (Glycemic Index). He also allows a once-weekly cheat day when you can eat anything you want. This diet can work, often for longer than more restrictive low-carb diets. I didn’t enjoy it for more than a month myself, however.
• Paleo & Primal – The theory behind these diets relates to how our ancestors at in pre-agricultural days, and how our bodies basically haven’t evolved to process grains, sugar or other agricultural foods. Dairy, grains, fruits, sugars and processed foods are restricted or eliminated in these diets. There are a lot of proponents of this diet, and moving from processed to whole foods has given people a lot of health benefits. Unfortunately, there isn’t a lot of science to support the theories — for example, we have evolved to be able to handle grains and dairy, according to anthropologists. Another problem is that people who do these diets often eat a lot of meat, which isn’t research-based and isn’t incredibly healthy at this kind of extreme.
• Mediterranean – One of the best diets out there, it’s based on traditional Mediterranean cultures that have less saturated fat and more olive oils, less red meat and more fish, lots of veggies and whole grains. It’s been shown to improve heart health and weight.
• Okinawan – The Okinawans have been shown to be perhaps the longest-living people on Earth, and the healthiest into old age. Their traditional diet has lots of veggies of all colors, and (contrary to low-carb and Paleo philosophies) has very little meat, mostly soy protein, and lots of carbs (80% of their calories were from carbs, mostly sweet potatoes but some rice). Okinawans traditionally ate little processed foods or sugars. It’s a good diet.
• Vegetarian & Vegan – I’m personally a vegan (mostly) and have been for years, and have found it to be healthy and sufficient in nutrients if you educate yourself a bit. It’s not difficult. It can be unhealthy if you eat mostly processed foods or vegetarian foods that are low in nutrients. It can be very healthy if you eat nutrient-dense foods (more on this below). I eat it not so much for health reasons (though again, it can be healthy) as for ethical reasons.
• Fad diets – There are a ton of them out there, and most are horrible. There’s the grapefruit diet, liquid diet, detox diet, juice diet, and more. If a diet relies mainly on one type of food, or tells you one type of food is evil, it’s probably a fad diet.

What I’ve learned: Through my own experiments and research with all of the above diets, I’ve found some things that are true:

1. Extreme diets are not necessary. If a diet restricts you incredibly, it’s probably not necessary. It will probably work for weight loss in the short term, because you won’t eat as many calories as usual, but extreme diets tend to be hard to stick to (though some people will always be exceptions). Note that while vegan diets might be considered extreme, I don’t do it because of health reasons — I do it for ethical reasons. And within the possibilities of veganism, there are actually a ton of options, so it doesn’t feel restrictive once you get used to it.
2. Less processed food is good. The best parts of most of the diets above are when people move from processed foods to less processed foods. Whole foods are healthier, in general, more full of nutrients and more filling.
3. Vegetables are king. All of the above diets tell you to eat veggies. Plant foods in general are full of fiber, nutrients, and all around good health. Green veggies are the absolute best, while veggies of all colors are awesome. Fruits, nuts, beans, seeds are also awesome.
4. Grains are fine. Reducing grain intake can be a good thing, if you replace them with veggies, good protein, nuts, seeds and beans. But a moderate amount of whole grains won’t hurt. Processed grains aren’t great and should be done in moderation.
5. Calories are also important. Many of the above diets work mostly because they restrict what you can eat in some way, and therefore restrict calories. If you eat fewer calories, you will lose weight, and for many people that will be a healthy change.

Foundation of an Optimal Diet

The following components are the most important elements of a healthy diet, and you should try to include them every day:

1. Vegetables & fruit. By far, one of the most important groups, and most people don’t get enough of them. We’ll go over how to incorporate more veggies into your diet in another article. A variety of vegetables is good — dark green ones are most important, but it’s good to have red, yellow, orange, along with some white veggies.
2. Beans, nuts, seeds. Good sources of plant protein, fiber, and good fats. I love raw almonds and walnuts especially, and incorporate ground flaxseeds into many meals. Lentils and black beans are among my favorite beans, though I regularly also use red and pinto beans, white and garbanzo beans.
3. Healthy proteins. For non-vegetarians, fish is the best protein, followed by the less fatty parts of poultry (not fried), and smaller amounts of red meat. Read more. Yogurt is also a good protein. For vegans, the above category of beans, nuts & seeds is great, along with soy protein such as tofu and tempeh, and seitan and other types of protein. (No, soy is not unhealthy.)
4. Healthy fats. Saturated fats should be kept to a minimum, despite what you might have read on the Internet (check sources to see if there is a good amount of peer-reviewed evidence behind claims that saturated fat is healthy), but instead of going low-fat, it’s good to replace saturated fats with polyunsaturated and monounsaturated fats — avocados, nuts, olive oil, seeds, and fish.
5. Healthy grains. While some groups on the Internet have a grain phobia, I haven’t seen any good evidence that whole grains are unhealthy. Processed grains, on the other hand, are often empty calories and should be avoided. Good grains include flour-less bread (sprouted grains), brown rice, quinoa, steel-cut oats and others.

Other Super Healthy Foods

Other than the above broad categories, a handful of foods offer a huge nutritional bang for your buck. I would try to include them on a regular basis:

• Dark leafy green veggies – These are the king of vegetables and should be eaten every day, as much as you like. Good green veggies include kale, bok choy, broccoli, collard greens, spinach. Put them in soups, sauté in garlic and olive oil, make salads, dice them small and put them in chili and spaghetti and other sauces, sandwiches, stir-frys and more.
• Berries – full of anti-oxidants, vitamin C and minerals, berries are good to satisfy a sweet tooth. I love them with yogurt or steel-cut oats, or as a snack.
• Dark chocolate – multiple health benefits have been found in recent years for dark chocolate, including lowering cholesterol and blood pressure. Read more. Chocolate might even have weight loss benefits. Most chocolate has too much sugar and fat, so get dark chocolate with as little of that as you can stand. Eat a square or two with berries for a delicious treat.
• Tea – green tea is full of health benefits — from anti-cancer to fat burning to lowering cholesterol and more. Drink whole-leaf green tea (avoid tea bags if possible) with good water, slowly and with joy. Hand-whisked matcha is good too. Oolongs are lovely whole-leaf teas that can be brewed for a couple hours.
• Wine – red wine is best, if you drink just a glass or two a day. Lowers risks of heart disease and cancer.
• Quinoa – A great grain substitute, full of protein and iron and other great nutrients. Cook and eat just like rice, with a tofu and veggie stir-fry on top!
• Sweet potatoes, squash & pumpkin – delicious and nutritious, eat instead of white potatoes or rice, or incorporate into soups.
• Yogurt – while I don’t eat dairy yogurt now that I’ve transitioned to vegan (mostly), yogurt has been shown to be a good source of protein and calcium, one of the best dairy choices, and non-fat yogurt is tied to lower weight (as part of a lower-calorie diet).
• Spices: Some of the healthiest spices include cinnamon, turmeric, chili pepper, garlic.

Meat vs. No Meat

Is meat healthy for you? Should you avoid it or eliminate it completely? Is it really so bad?

I’m not going to be able to provide a definitive answer to that question here, but I’d like to make a few points about meat:

1. No, it won’t kill you. That’s probably the last thing you’d expect to hear from a vegetarian, but honestly, including some meat (especially poultry and fish) can be very healthy. It really depends on how you do that. That said, again, I don’t eat meat for ethical reasons, and I’d recommend you consider those issues as well.
2. Excessive red meat can be unhealthy. Studies have linked eating more than half a serving a day of red meat to cancer and cardiovascular disease deaths. That’s not to say you have to eliminate it completely — but eating less than most people eat is a good idea.
3. Fish can be very healthy. If I weren’t vegan, I would probably eat mostly fish for protein. There are health problems to consider with fish (mercury, etc.) but in general fish protein tends to be one of the healthiest proteins possible. Poultry is also good, but without the good fats that fish have.
4. Eliminating all meat can be healthy as well. There are lots of forms of protein that come from plants, and in general plant protein is very healthy. If you eat a variety of plants, you’ll have no problem getting protein — beans, nuts, tofu, seitan, tempeh, seeds, grains, even veggies all have protein. You don’t need meat to be healthy.

Other Important Nutrients

What other nutrients besides protein do you need to worry about? Actually, there are a host of them, but some important nutrients include:

• Calcium – important for bones, many women don’t get enough (though older women should get calcium from dietary sources and not supplements). It’s a good thing for vegans to look out for too. Dairy, of course, is an important source, but calcium can be found in many plant foods such as dark leafy greens, almonds, and is also in fortified soy milk, tofu and soy yogurt.
• Iron – another important nutrient, it can be found in red meat but also in dark leafy green veggies and nuts. As you can see, vegans should include lots of dark leafy green veggies and nuts for a variety of reasons, but they’re good for non-vegans as well. Iron deficiency is the most common deficiency in the world, vegans and non-vegans alike. Read more.
• Vitamin D – also important for strong bones, for immunity, and cancer prevention. It is found in fortified milk, along with salmon, mackerel, tuna and sardines. Vegans can find Vitamin D in fortified foods such as soymilk. It’s important to note, though, that our bodies can manufacture this vitamin without the need for dietary sources if we get adequate exposure to sunlight — usually 10-15 minutes of sun on our skin, 2-3 times a day, though more is needed in winter months for many areas.
• Vitamin C – an essential vitamin that provides multiple health benefits, including prevention of cancer, heart disease and cataracts. About 90-100 milligrams a day is recommended for optimal health. Great sources of Vitamin C include berries, peppers, green veggies, citrus fruits and other fruits & veggies. Read more.
• Vitamin B12 – really only a problem for vegans, as B12 is found in animal products such as meat and dairy. It’s not hard for vegans to get B12 if they include fortified foods such as soy milk, soy yogurt, a multi-vitamin, or nutritional yeast.
• Zinc – An essential mineral that is used virtually everywhere in the body in many ways, you only need a small amount, and while it’s highly available in red meats, oysters and lobster, it’s also available in many plants (especially beans, nuts and whole grains). Read more.
• Magnesium – another highly essential and widely used mineral, it helps maintain normal muscle and nerve function, keeps heart rhythm steady, supports a healthy immune system, and keeps bones strong. Good sources include green veggies, beans, nuts, seeds, whole unprocessed grains. Read more.
• Healthy fats – Not all fats are bad for you. Polyunsaturated and monounsaturated fats lower disease risk. Good sources include vegetable oils (such as olive, canola, sunflower, soy, and corn), nuts, seeds, and fish. One type of polyunsaturated fat, Omega-3 fatty acid, is especially good for your heart — find it in cold water oily fish, such as salmon, herring, mackerel, anchovies, and sardines … but also plant sources such as chia seeds, flaxseeds (or linseeds), and walnuts.

Foods to Avoid

I don’t believe that any foods need to be completely eliminated from a healthy diet, but it’s clear that some foods can cause health problems when eaten in excess.

So while you don’t need to be afraid of the foods below, I would eat them in moderation — and if you eat a lot of them now (several times a day), I would reduce your intake of them over the long term:

• Processed (or refined) grains – While whole grains can give you fiber, minerals and energy, refining grains remove almost all the nutrients from the food and leaves you with the equivalent of sugar. Your body processes this very quickly and, if it’s not used as energy, it will be stored as fat. So you get excess energy with almost no nutrients. Examples include white bread, white rice, pastries, bagels, pizza crust, most cereals, cakes — anything made with white flour. Read more.
• Sugars – In general, excess sugar isn’t good for you. While your body can use it as energy, it can also get energy from other places that also have nutrients — nuts, whole grains, beans, fruits, healthy fats, etc. So sugar ends up giving you little nutrition for the calories you get from it. While the negative health effects of sugar have been overblown, the fact remains that sugar-laden drinks and desserts are a good way to get excess calories that lead to obesity.
• Saturated and trans fats – This will be one of the most controversial items on this list, mostly because a number of vocal groups on the Internet claim that saturated fats are good for you (trans fats are generally agreed to be something to avoid as much as possible). But I’ve done a very broad examination of the scientific evidence, and it’s clear that while more research needs to be done on saturated fats, the bulk of the evidence shows that we should reduce our intake of saturated fat … and replace it with unsaturated fats, not starches. This is the conclusion from the recent Cochrane Review of 48 studies conducted between 1965 and 2009 that included 65,508 participants: that “reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14%” and that most people “should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates”. In 2003, the World Health Organization (WHO) and Food and Agriculture Organization (FAO) expert consultation report concluded that “intake of saturated fatty acids is directly related to cardiovascular risk. Recommendations to reduce or limit dietary intake of saturated fats are made by Health Canada, the US Department of Health and Human Services, the UK Food Standards Agency, the Australian Department of Health and Aging and many other such bodies that have reviewed the scientific evidence. Read more.
• Fried foods – In general, fried foods have more fat and therefore more calories than most foods, and as such they should be avoided. Eating fried foods has been linked to increased obesity, though a recent study of people in Spain indicates that it’s possible to eat fried foods and not have increased risk of cardiovascular disease. It should be noted that in Spain, they frequently cook with olive oil and don’t re-use their frying oil as is often done with fried food in the U.S.
• Diet sodas – Many people believe switching from soda to diet soda is a healthy alternative, and there is some truth to that, but the evidence doesn’t show great results for those who drink diet soda. I’d stick to water or tea if possible.
• Alcohol – While there is evidence that small amounts of alcohol has heart benefits (1-2 drinks a day for men, 1 drink a day for women), there are numerous health risks for those who drink more than that regularly for a long period of time. Read more.
• Dairy – While there are some health benefits to consuming moderate amounts of dairy, there are health concerns as well: two-thirds of the world’s population is lactose intolerant, there are high levels of saturated fat in many dairy products, and there are links to prostate and other cancers, among other concerns. Dairy isn’t a necessary ingredient to a healthy diet, and I’d recommend that it be consumed in moderation.

Liquids

So what should you drink? There are so many choices, and I’ll make some recommendations below:

• Water – perhaps the best drink possible. Tap water is fine in most places, even if it doesn’t taste as good as filtered water. Mineral water isn’t necessary. Also note that while most people think you need 8 glasses of water a day, that includes the water in your food and other things you drink (tea, milk, etc.). So drink plenty of water, but don’t feel you need to overdo it. I would go for 4-5 glasses of water a day, depending on how much exercise you get and how much you’re outdoors and sweating. Aim for lighter colored urine (as a guide) not clear but not dark.
• Tea – very healthy for you, especially if you drink it without sugar. Green tea, especially whole leaf green tea (not from tea bags) has the most health benefits. A daily tea ritual is a good thing.
• Soda – Eliminate soda if you can. There are no health benefits, and basically it’s extra calories and bad for your teeth. Diet sodas are useless. Drink tea if you don’t want to just drink water.
• Coffee – not bad in moderation. Moderate amounts of black coffee is good for you, but too much can give you caffeine problems. Sugary coffees such as lattes and mochas are unnecessary and should be consumed in moderation.
• Wine – Red wine in particular can have good health effects, in moderation. A daily glass or two of wine is healthy. Women should probably not drink more than a glass, and men not more than 2-3 glasses (depending on how big you are) each day, except on occasion.
• Beer & hard alcohol – There is nothing wrong with a beer a day, or a small amount of harder liquor. More than that shouldn’t be consumed too often — maybe once every week or two.
• Milk – There is mixed research on dairy, so whatever I say here will be controversial. I avoid dairy for ethical reasons, but don’t believe that it’s unhealthy in moderation. Dairy contains protein and calcium, though full fat dairy contains a lot of saturated fat that probably isn’t good in excess. There are those who disagree with this, but I haven’t seen any good research that supports the “saturated fat is good for you” position.
• Vitamin water – unnecessary. Regular water is best.
• Sports drinks – unnecessary for most people. If you’re just exercising for an hour or less, you don’t need sports drinks. If you’re exercising for close to two hours (or more), then sports drinks are good to replace sugars and electrolytes.

When & How Often to Eat

Does it really matter how many times you eat throughout the day? How many meals are optimal? When should you eat? Is fasting good or bad for you?

The short answer is no, it doesn’t matter.

I’ve personally tried a variety of meal timing approaches for at least a month at a time (sometimes for several months), and none of them made any difference in terms of health and weight loss.

Here’s what I’ve tried:

• Six meals a day – Actually, I’ve even done seven and five meals a day. They are all fine. The main benefit of this meal frequency is that you are rarely very hungry, because you haven’t gone very long since your last meal. So it helps for those who have issues with appetite. The main disadvantage is that you have to eat very often, which means more time spent prepping for meals, and it’s a lot of work.
• Intermittent fasting – I’ve done several versions of IF, from one meal a day to two meals a day to a six- or eight-hour eating window. I’ve found that you can adjust to smaller eating windows — instead of eating from when you get up to when you go to bed, you only eat from noon to 8 pm, for example. It’s a matter of gradually eating your first meal later, and you find that your hunger patterns adjust. There don’t seem to be any health downsides to this approach, though I didn’t find that many benefits either. The best benefit I found is that if you eat less often, you have fewer meals to make. Getting very hungry can be a problem for some people, especially if you don’t gradually adjust.
• Timing meals around workouts – a lot of hard-core fitness folks do this. Basically, you eat the majority of your calories (including carbs and protein) around your weight workout — before and after. This should shunt the calories to building muscle rather than fat. It’s not a bad idea, though I’ve found it doesn’t make a huge difference.
• Three or four meals a day – I personally stick with this. Basically it’s a small breakfast, late in the morning, then the same meal for lunch and dinner (so I only need to prepare one meal), and a healthy snack in between. It’s simple and easy.

Portion Sizes

Are portions sizes important, and what are the optimal portion sizes?

The short answer is yes, portion sizes do matter.

An abundance of calories is what makes people overweight. There is evidence that the number of calories isn’t the only thing that matters (composition of calories is a factor), but by and large, if you consume too many calories, you will gain weight over time.

There are a couple ways to take in too many calories: by eating large amounts of food, or by eating foods that are calorie-dense. Calorie-dense foods are high in calories for their weight — examples would include fat and oil and really anything high in fat or oil, like nuts, meats, fried foods, and dairy.

The healthiest groups of people, such as the traditional Okinawans, Mediterranean cultures, and Japanese, on average eat fewer calories than more modern societies that tend to be not only overweight, but higher in heart disease, diabetes, and other lifestyle diseases. Reducing calories is one of the best ways for people who are overweight to get healthy quickly (there are other good ways, like exercise, eating more nutrient-dense foods like vegetables, and meditation, for example).

Portion sizes can easily get out of hand, and result in too many calories. Fast food places supersize meals, while chain restaurants in the U.S. tend to serve huge platters of food, and people in Western societies often snack on junk food throughout the day.

So while portion sizes aren’t everything, they do mater. Reducing portion sizes is a good way to keep calories in check, while enjoying a variety of foods (even smaller amounts of unhealthy ones). Another approach would be to eat huge portions of foods that aren’t dense in calories, such as lots of veggies, fruits, and some whole grains.

If you’re looking for a rough guideline, keep protein and whole grains each to a portion the size of your fist. Then eat as many veggies and fruits as you like. Have a few bites of dessert if you like, but don’t overdo it.

Putting It All Together

So, considering all of the above information, what is the optimal diet? The truth is, there isn’t one answer, but the following guidelines should help create an amazingly healthy diet:

1. Plan meals that incorporate the healthy foundation foods. It’s good to think through your meals in advance, before you get hungry, and perhaps plan several dishes to eat throughout the week. I will cook several days worth of veggie chili or tofu or tempeh stir-fry, for example, so that I don’t have to worry about preparation for every meal. Try to find meals that don’t take a ton of work to prepare, that can be cooked in large batches, and that include lots of veggies, along with beans, seeds, nuts, healthy protein, healthy fats, and a moderate amount of healthy grains.
2. Have a healthy breakfasts. Eating breakfast usually means you’re less hungry later in the day, and usually means you won’t grab a muffin or croissandwich. A couple of my favorite healthy include steel-cut oats with berries, flaxseeds, raw almonds, raisins and cinnamon … or Greek yogurt with berries, raw almonds, and flaxseeds.
3. Eat mindfully. Mindful eating means you can stop when you’re full, and fully enjoy the food rather than being left unsatisfied when you’re done eating. It means you can enjoy social occasions without overeating, and eat unhealthy foods sometimes without overdoing it. It means you enjoy healthy foods more, because you learn to appreciate their often subtler tastes.
4. Plan healthy snacks. There will likely be a time between meals when you start getting hungry, and if you don’t have healthy snacks planned, you’ll grab whatever’s convenient, which is not likely to be very healthy. I enjoy nuts and fruit as a quick, easy, healthy snack.
5. Have tea, dark chocolate, berries & wine each day. It’s important to eat healthy foods that you can savor, and these four foods tend to do it for me. A daily tea ritual in the morning or afternoon is relaxing and enjoyable. A bit of dark chocolate with berries helps satisfy any sweet cravings, and gives you a ton of anti-oxidants — savor this treat slowly. A glass or two of wine helps keep heart disease away, and makes a nice end-of-day relaxing ritual.
6. Variety is good. While it’s not a bad idea to make large batches of meals that you can eat for several days, over the course of a month, you should switch the meals up, so that you get a variety of veggies, protein sources, healthy fats, whole grains. It gives you a variety of nutrients, and also helps keep things interesting.
7. Allow yourself the less-healthy foods in moderation. It’s unhealthy to be afraid of any kind of food, even if it’s unhealthy, and making yourself feel very restricted is likely to result in binge behavior. Instead, allow yourself some fried foods, fatty foods, sweet treats, processed bread … but in smaller amounts, and on occasion, instead of all day long.