Healthy food, regardless of food category, has a large breadth and high density of essential nutrients, a high fiber-to-sugar ratio, a low sodium-to-potassium ratio, and low saturated fat content. This ultimate guide and resource page will help teach you how to identify healthy food, as well as provide you with lists of the healthiest foods from various food categories rigorously analyzed by nutrient content.
To have a healthy diet, you must eat healthy food. But just how much healthy food do you need? Does your entire diet need to consist of healthy foods? If not, how low can the percentage be? 80%? 50%?
Most of the world is waking up. We’re starting to realize just how important a healthy diet is for a healthy life. In fact, large studies published in journals like Lancet show your diet is the leading behavioral disease risk factor in the world, leading to roughly 1 out of every 5 deaths globally.
Most of the illness derived from unhealthy diets relate to chronic diseases such as cardiovascular disease, diabetes, and some cancers.
And just as the name implies, these conditions arise after years, sometimes decades, of poor, chronic lifestyle behaviors.
This is important to understand.
Poor health won’t develop overnight after eating an entire pizza and drinking a soda to wash it down.
So we can safely say that 100% of your diet does not need to come from healthy foods. Yes, enjoy your birthday cake.
But it also probably isn’t a stretch to convince you that 0% of your diet coming from healthy foods cannot lead to good health.
Chronic diseases arise when these behaviors are repeated on a regular basis, often over the course of a lifetime.
Our bodies are quite resilient in the short term, capable of adapting to varying needs. You could imagine early hunter-gatherers might have had variable food supplies from time to time. We can adapt over short periods of time to maintain health and cognition.
But the foods those hunter-gatherers did eat were quite different than many of the processed foods we eat today.
Sometimes, when trying to understand what something _IS_, it’s useful to learn what it ISN’T.
Healthy foods contain an abundance and breadth of essential nutrients required for good health. They also lack large quantities of nutrients that promote poor health outcomes.
Therefore, unhealthy food, by definition, is the opposite.
Food becomes less healthy in three ways.
Let’s take a look at the first one.
As the concentration of essential nutrients goes down, the food item in question becomes less healthy.
One reason we need to eat food is to obtain calories. We use these calories for energy that in turn powers metabolism, respiration, the circulatory system, protein production, and everything else that keeps our bodies alive.
But another reason we eat food is to obtain nutrients essential for various metabolic processes. These essential nutrients, including most vitamins and minerals, are required for life but they are only found in our diets.
We only consume so many calories each day.
Therefore, we need these essential nutrients to come along for the ride.
If the foods we are eating do not have sufficient concentrations of these essential nutrients, our bodies will be operating in a sub-optimal condition.
If your consumption of these nutrients drops too low, you may develop a severe deficiency that leads to very poor health conditions. Although this level of nutrient deficiency is rare in the developed world, these deficiencies are still very prevalent in poorer nations.
But even chronic, low levels on essential micronutrients may still be leading to poorer health outcomes.
For example, studies suggest that subclinical vitamin D intake can lead to declines in musculoskeletal health1 and that adding vitamin D and calcium supplementation to the diets of the elderly can help prevent osteoporotic bone fractures.2
And the average intake of fiber in the U.S. is very low. A low intake of fiber will not immediately cause sickness, but studies show that chronic underconsumption of fiber may lead to greater risk of all-cause mortality.3
One prime culprit for turning healthy food into unhealthy food is sugar.
Sugar is one nutrient that unabashedly finds its place into all three categories we’ve outlined as constituting what makes food unhealthy.
Sugar is a carbohydrate, and thus caries with it roughly 4 calories for every gram.
But along with those 4 calories, no essential nutrients come too.
While adding sugar to food may make it taste better, it can either displace calories you would need to get elsewhere that _do_ carry useful nutrients, or it can add to your daily calorie intake and therefore lead to weight gain.
Speaking of sugar…
The best diets are well-balanced with healthy food in modest portions.
When diets get out of balance for too long, problems can develop.
One way your diet can get out of balance is by choosing foods with high concentrations of compounds known to increase your risks of developing chronic diseases.
Picking up where we left off, sugar is one of these compounds.
The World Health Organization recommends that fewer than 10% of your daily calories should come from sugar. Ideally, they suggest reducing that further to less than 5%.
One reason that sugar may need to be kept to a minimum is due to its glycemic load.
The glycemic index (GI) is used to represent the body’s response to digesting carbohydrates. Specifically, the impact this has on blood glucose levels after eating.
Glucose is set as the standard with a GI of 100.
Table sugar (sucrose) has a GI of around 63.
Diabetes is associated with the development of insulin resistance, where the body is less capable of using insulin to help control blood glucose levels after meals.
A low-GI diet is often recommended for those with diabetes.4 Thus, removing sugar from your diet would naturally help lower your diet’s GI-score.
Note: This is not medical advice. Please consult your doctor before making any dietary changes.
Nevertheless, the direct link between sugar and disease is not so clear, as stated by the American Diabetes Association who identifies a link between sugar-sweetened beverages and diabetes but stops short of saying sugar directly causes diabetes.
Other, general population studies, however, point to a possible link with heart disease.5 This study published by Harvard researchers in JAMA suggests added sugar, in light of an otherwise healthy diet and healthy weight, may still increase risk of heart disease.
While the science continues to get sorted out, what’s clear is that all major health organizations suggest we should eat less sugar. Needless to say, healthy foods contain no added sugars.
Sugar-sweetened beverages are one of the biggest culprits. It is fairly easy to say, unequivocally, that sugar-sweetened beverages are not healthy foods.
Fiber helps attenuate the insulin response to eating foods like sugar.6 This is one reason why fruits are still incredibly healthy to eat despite their high sugar content.
Therefore, healthy food has a high fiber to sugar ratio.
Harvard Health recommends a ratio of 10 to 1, fiber to carbs ratio, because this is close to the ratio in unrefined whole grains. This ratio includes all sources of carbohydrates, including sugar.
Another nutrient linked to poor health when consumed in large amounts is sodium. Sodium is primarily found in salt.
In the general population, increased sodium intake raises both systolic and diastolic blood pressure; and with it an increased risk of stroke and coronary heart disease.7
Rest easy knowing salt added to healthy food cooked at home does not cause the level of concern noted by health organizations. In fact, roughly 80% of the overconsumption of sodium comes from restaurants and processed, packaged foods.
Salt is generally added to give flavor, but also to help preserve packaged foods. Unfortunately, sodium can lead to hypertension (high blood pressure), a major risk factor for things like stroke, heart failure, and kidney disease, to name a few.
But in addition to sodium’s hypertensive effects, minerals such as potassium8 and calcium9 have hypotensive affects. In other words, these nutrients can help neutralize some of the blood-pressure-raising effects of sodium.
This is where the concept of the sodium-to-potassium ratio comes from.
Having a lower sodium-to-potassium ratio has been shown to be associated with a lower risk of cardiovascular disease and mortality.10 In fact, Paleolithic hunter-gatherers are suspected of having a sodium-to-potassium ratio of 1 to 16. Our modern, Western diets, on the other hand, are closer to 1.36 to 1 – they’re so different the ratio actually inverted!
Therefore, healthy food generally has a lower sodium-to-potassium ratio.
The final nutrients to address are also one of the most controversial as of late.
Not all fats. Specifically, saturated fats.
First, we’ll discuss trans-saturated fats. These are not controversial. Nearly all researchers agree that trans fats are not beneficial for health, and major health organizations are trying to ban industrial production of trans fats from the global food supply chain.11
But saturated fats have caused a bigger stir (see article about the controversy of saturate fat intake and health).
Despite some uncertainly in the science and a passionate community of resisters, the scientific consensus still agrees that replacing saturated fats with polyunsaturated fats (not with carbohydrates), produces a modest reduction in cardiovascular disease risk.12
The issues surrounding dietary fats and cardiovascular health primarily relate to their effect on cholesterol levels. Specifically, how much they raise or lower both HDL and LDL.
While different fatty acids (for example, palmitic acid vs. myristic acid) result in different changes to HDL and LDL levels, saturated fats generally cause a modest increase in the LDL/HDL ratio while unsaturated fats cause a slight decrease in this ratio.13 This understanding, along with epidemiological studies, has been the mechanistic driving force behind specific fatty acids and healthy food.
Therefore, healthy food has zero trans fats and low saturated fats.
To recap, our understanding of healthy food through the lens of unhealthy food, healthy foods have:
Unhealthy foods loaded with unbalanced nutrients aren’t the only path towards poor nutritional health.
Even healthy food can become unhealthy when eaten in excess.
No matter how many essential nutrients a food might have, or how little sugar or trans fats present, overconsumption of calories at a rate higher than you burn them will lead to weight gain. Period.
And over time, this weight gain, if left unchecked, can lead to overweight and obesity. These conditions are known to lead to increased risks of most major chronic diseases we face today.14
Even fruits and vegetables?
Technically, yes. Although, in reality, this would be extremely difficult to do. The high fiber content of fruits and vegetables increases satiety and causes you to feel fuller for longer. This is one of the reasons eating plenty of fruits and vegetables can help you lose and maintain a healthy weight while ensuring you get plenty of essential nutrients.
But other foods that are reasonably healthy foods that are eaten in excess over time, coupled with little physical activity, can lead to weight gain and the poor health consequences that accompany it.
This is where much of the trouble of overconsumption comes from. Foods that are moderately healthy. Fruits and vegetables are not the problem (in fact, they are, unequivocally, the solution). But foods that have plenty of nutrients but can easily be overconsumed, need to be kept in check too.
So as with all things, healthy food should be eaten within moderation as part of a healthy diet and well-balanced lifestyle.
You’ve heard the advice before.
Eat a well-balanced diet.
But what does that mean?
Essentially, a well-balanced diet is beneficial for health because you need a wide variety of essential nutrients for health. A well-balanced diet helps you obtain these essential nutrients by eating a variety of foods high in different ones that, in the end, provides you with necessary amounts of all of them.
A well-balanced diet is also important because many compounds, even those deemed essential for life, have an upper limit.
In other words, many nutrients live in a Goldilocks zone – not too much, not too little.
But some healthy food has an abundance and breadth of essential nutrients while limiting the abundance of nutrients you shouldn’t overdo on.
And other foods are not as bad as you might think, as long as they are not overconsumed to excess.
With a few exceptions, most foods can find their way into any balanced diet.
A good rule of thumb is to gauge the frequency with which you eat them relative to their level of healthy-ness.
Foods high on the list of healthiest foods (high nutrient density score) should be eaten more often (higher frequency). Sliding down the scale, as foods drop per their relative nutrient density score, the less frequency you should eat them.
To provide a visual comparison, the individual foods analyzed were categorized into food groups and plotted as a histogram. That means, this plot shows how many foods in each category showed up for any given nutrient density score.
For a comparison, individual food items were compared against “fast foods.” Keep in mind, fast foods are often “meals,” consisting of multiple food items. For example, a vegetarian Subway sandwich with lettuce, tomato, and onion might fall on the higher end of the nutrient density score, while a Wendy’s Frosty falls on the low end.
The nutritional content of each food item was obtained from the USDA Food Composition Databases.
The nutrient density score is the full, composite score for each food item. This score is intended to be used across food groups to compare nutrition quality of each food item.
The nutrient density score is the summation of:
The Mineral Density Score and the Vitamin Density Score were weighted similarly. The density of each micronutrient was determined on a per-calorie basis. To enable equal comparison, the total density was then scaled to an equal 2000 calorie quantity for each food item. The quantity of each micronutrient on a per-calorie basis scaled to 2000 calories was then compared against the daily reference intake (DRI) for that specific micronutrient. This value represents the percentage of your daily micronutrient needs as provided by that particular food item on a per-calorie basis.
This value was then weighed for a final score from 0 to 1. A percentage at or above 100% of your DRI was met on a per calorie basis, a value of 1 was given. Similarly, if no micronutrient was present, a value of 0 was given. The middle…
The Macronutrient Balance Score was determined using the density of proteins, fats, and total carbohydrates as a percentage of total calories. The grams of protein, fat, and total carbohydrates were converted by 4, 9, and 4 kcal/gram, respectively. The percentages were compared against USDA Dietary Guidelines for an adult on a 2000 calorie diet and given a score of 0 for each that fell within the recommended range. For those that fell outside of the range, a negative score was given. The negative score was determined using the same linear function for each macronutrient. A slope m=0.33/0.65 was chosen so that the sum of each macronutrient score could not exceed -1.
The Fat Quality Score was determined using the distribution of saturated, monounsaturated, and polyunsaturated fatty acids. The cholesterol quality was determined using the equations derived from Mensink, et al.13 to reflect changes to the LDL:HDL ratio. This cholesterol quality score was normalized by multiplying the percentage of calories attributed to total lipids for each food item. In addition to the overall cholesterol score, each score was further modified by the saturated fat content. The USDA Dietary Guidelines recommend less than 10% of your total caloric intake should come from saturated fats. Therefore, the percentage of calories coming from saturated fats was determined and a negative value was assigned using a linear equation with a slope m=-1/0.9. This value was added to the cholesterol score to yield the Fat Quality Score.
The Fiber Score was determined first by calculating the percentage of your DRI on a per-calorie basis using a similar method as for micronutrients. Because increasing fiber has shown dose-dependent benefits without an upper limit, the logarithm of this value was calculated and added to a value of 1 to yield the fiber score.
The Sugar-to-Fiber Ratio Score was determined by taking the ratio of sugar to fiber in grams because fiber has been shown to attenuate negative postprandial insulin and blood glucose responses. This ratio, representing a more positive or negative sugar to fiber profile, was then multiplied by the total amount of sugar and inverted to give weighted, negative results.
The Sodium-to-Potassium Ratio Score was determined by taking the ratio of sodium to the sum of potassium and calcium because the hypotensive properties of potassium and calcium have been shown to attenuate the hypertensive properties of sodium. This value was multiplied by 2.1516 to represent an increase risk of mortality from stroke (63%) and coronary heart disease (32%).7
Not all food items in the USDA Database will be accurate and applicable across all, actual food items. In addition, many nutrients were not accounted for by all food items. In these cases, a zero was assumed. This assumption may not be accurate for all nutrients.
The scoring and weighting methods are not viewed as a field-recognized method for comparing foods. There did not appear to be an accepted method for this kind of comparison, so these methods were developed on our own. Each micronutrient was compared equally under the assumption that each micronutrient is considered essential for life and equally necessary in the diet. Also, excessive concentrations of these micronutrients were not given additional value, as many micronutrients are simply excreted in excess and others may even begin to impart negative effects at high concentrations. These negative effects, if applicable, were not accounted for. Other weighting schemes for fat quality, fiber quantity, and ratio scores are subject to debate. These methods may not accurately weigh their effects on health on a level predictable by randomized control trials or observational studies.
Despite these assumptions and limitations, these comparisons should provide a decently accurate depiction of their relative density of nutrients and provides a high-level overview of their comparison to other foods on a equal scoring system.
Vegetables are best in show among the healthiest foods you can eat.
They are dense in a broad array of micronutrients and other beneficial phytonutrients, they generally have low concentrations of sodium, sugar, and saturated fat, and they are high in fiber.
Essentially, they are high in things that are good for you, and low in things you should limit. The definition of healthy food!
High among the list of the healthiest vegetables are leafy greens. Almost all green leafy vegetables rank high on the list of healthy foods.
Collards, as in the entire vegetable rankings, takes the top spot. But if you’re curious, take a deeper dive into the analysis of the healthiest green leafy vegetables.
Leafy greens get most of the attention when it comes to healthy vegetables, but beans are some of the most nutritious, healthy foods you can find.
They’re packed full of nutrients, high in fiber, and often are a great source of protein.
Fresh herbs are great additions to your meals not only because they pack a punch when it comes to flavor, but they pack a nutritional punch too.
Like beans, nuts can sometimes get overlooked when trying to find healthy food. But their bite-sized nature makes these great for healthy snacks, as well as toppings on salads or other dishes.
Nuts are high in micronutrients, healthy fats, protein, and phytochemicals. See the full nutritional breakdown of the healthiest nuts.
Not far behind vegetables, when it comes to healthy food, is fruit. Many fruits are also some of the healthiest foods you can find.
High in micronutrients, fruits are also high in fiber, which helps attenuate their high sugar content and render these treats tasty and nutritious. They truly are nature’s candy.
Bread has gotten a bad rap from the low carb movement. And while it’s best not to eat bread in excess, many breads can proudly sit high on the rankings of healthy foods.
Whole grain varieties contain bountiful micronutrients and plenty of fiber.
So why does bread get such scolding?
Refined, white breads get stripped of much of their nutrient content and fiber – two of things that make whole grain varieties healthy foods.
Discussing the health effects of vegetable oils means discussing the health effects of fats.
Fats are another controversial topic in many diet and nutrition circles online. Yet, the consensus among nutrition and public health researchers is in much less debate.
Fats are an essential component of your diet, but the constitution and breakdown of the fatty acid contents of the fats you consume is what’s up for debate.
Polyunsaturated fats, monounsaturated fats, saturated fats, and trans-saturated fats are all groupings of fatty acids that can each be broken down further into specific fatty acid molecules of different varieties.
Each fatty acid produces different effects on your LDL and HDL cholesterol levels – proteins in your blood that regulate a host of biochemical processes and are implicated in cardiovascular health.
Thus, the fatty acid breakdown of various vegetables oils can help you navigate some of the heart-health implications of different varieties.
Nevertheless, vegetables oils, like olive oil, are consumed in large amounts among some of the world’s healthiest communities.
Vegetable oils are great additions to your diet. See our deeper analysis of vegetable oils and health.
Cheese is delicious, yes. But we don’t consider cheese a healthy food. And cheese is certainly not essential for a healthy diet.
Nonetheless, cheese can happily find its way into any healthy diet.
Just like dessert, cheese, when eaten in moderation, can find its way into good health.
Many cheeses have a poor fat profile and some have high sodium content – two areas of concern for many on traditional Western diets.
But they can also contain many micronutrients.
Don’t consume cheese in large amounts. But when you do indulge and are looking for healthier options, see our detailed analysis of the healthiest cheeses.
When it comes to assessing your intake of healthy foods, there are many approaches you can take. Some techniques are better measuring outcomes like weight and visceral fat. Others are designed to monitor nutrient intake on a routine basis.
Each technique is useful for achieving different goals, but all of them help you acquire personal nutrition data. This nutrition data can be collected in myriad ways and used to personalize and optimize your nutritional health.
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