The Levels Dietary Guidelines

Nutrition advice is complex and individualized, but here’s our best synthesis of five years of Levels guidance.

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Updated: 03/31/2025|13 min read

For decades, the USDA Dietary Guidelines for Americans have served as the cornerstone of nutritional advice in the United States. Viewed in the best light, these guidelines represent a good-faith effort among hundreds of researchers, doctors, and experts to synthesize mainstream medical opinion and research into simple principles that can help guide American’s choices. They shape food policy, school lunch programs, and public health initiatives nationwide.

However, as a product of the political process, government dietary guidelines are inescapably subject to lobbying, industry capture, and necessary compromise. These factors can lead to overly conservative guidance and concessions. For example, in developing the 2020-2025 Dietary Guidelines, the scientific advisory committee strongly recommended limiting added sugar to less than 6 percent of daily calories based on the available evidence. Yet the final guidelines maintained the previous 10 percent threshold—a decision that some experts suggest reflects the influence of food industry interests rather than the strongest scientific consensus. (By contrast, we would recommend that 0 percent of your daily caloric intake should come from added sugars but that you should instead aim for healthier carbohydrate sources. We’re not saying never eat sugar, but don’t consider it a necessary part of your diet.)

So, as a private company not bound by political constraints, we want to offer our alternative—one that reflects emerging research on optimal nutrition, disease prevention, and overall wellness, while recognizing—in fact, insisting—that there is no one-size-fits-all dietary approach. The Levels Dietary Guidelines don’t claim to have the extensive analysis behind the government recommendations—literally a years-long process. Instead, they aim to distill what we’ve learned about nutrition over the past five years into practical principles that most people can follow, which will lead most people to better health if followed with consistency.

Finally, they aren’t meant to be prescriptive. The ideal diet varies significantly from person to person based on genetics, cultural traditions, taste preferences, food availability, budget constraints, and individual physiological responses. What works well for one person may not work for another. These principles should be viewed as a starting point for exploring what works best for your body and lifestyle.

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1. Prioritize whole, minimally processed foods

Choose foods that exist in nature rather than those created in food manufacturing facilities.

Unprocessed and minimally processed foods—vegetables, fruits, meat, fish, eggs, and nuts—should form the foundation of your diet, full stop. These foods retain their natural nutrients and fiber, which help regulate blood sugar, support gut health, and fuel your body’s machinery. Unlike ultra-processed foods, which are associated with increased risk of obesity, diabetes, and heart disease, whole foods generally don’t contain added sugars, unhealthy fats, or artificial ingredients that can disrupt health.

Ultra-processed foods make up nearly two-thirds of the calories in the typical American diet, not because we want to be unhealthy but because they are designed to be hyper-palatable. They trigger salt, fat, and sugar cravings and too often lead to overconsumption. While there is research questioning precise causality, these foods have been linked in dozens of studies to inflammation, weight gain, and various chronic diseases. They also tend to foster less diverse gut microbiomes, which can further compromise health.

When shopping, focus on foods without labels or with very short ingredient lists containing recognizable foods. The more a food has been modified from its natural state, the more likely it is to negatively impact your health. Even seemingly healthy packaged foods like granola, protein bars, or plant-based meat alternatives often contain additives that may have detrimental long-term effects.

Remember that minimal processing doesn’t mean no processing—foods like frozen vegetables, canned beans (without added salt or sugar), and plain yogurt can be excellent choices that offer convenience without sacrificing nutritional benefits.

50 nutritious foods with metabolic health benefits

2. Minimize added sugars and refined carbohydrates

Aim to eliminate added sugars and dramatically reduce refined carbohydrates to support long-term health.

Added sugars—whether from table sugar, honey, maple syrup, or the dozens of other names sugar goes by on ingredient lists—provide calories with virtually no nutritional value. The average American consumes about 17 teaspoons (71 grams) of added sugar daily—far exceeding recommendations (which are themselves too high), and very likely contributing significantly to the current health crisis, as glucose and insulin are tied to most of the 10 common causes of death.

That’s because consuming excess added sugar and refined carbohydrates over time can lead to chronically elevated insulin levels, which can lead to Type 2 diabetes, cardiovascular disease, and other chronic conditions. These foods can also contribute to non-alcoholic fatty liver disease, systemic inflammation, and unhealthy alterations in blood lipids.

Refined carbohydrates in white bread, pasta, crackers, and other flour-based products are similarly problematic. During processing, the fibrous bran and nutrient-rich germ are removed from whole grains, leaving only the starchy endosperm. This creates simple carbohydrates that are quickly digested and converted to glucose, contributing to chronic elevation of blood sugar and insulin when consumed regularly.

Reducing or eliminating added sugars and refined carbohydrates can help stabilize energy levels, reduce cravings, and support overall health. Even natural sugars found in fruit juices can have adverse health effects when consumed without the fiber present in whole fruits, so eat the piece of fruit when you can.

8 Natural sugars that are not healthier for you

Why fructose is bad for metabolic health

20 low-carb dinner ideas that satisfy

3. Prioritize protein and fiber with each meal

Include adequate protein and fiber sources with every meal to support satiety, muscle health, and digestive wellness.

Protein and fiber are essential nutrients that support multiple aspects of health and are often under-consumed in typical Western diets. Both nutrients support various processes in your body, from muscle development to a healthy gut, as well as slow digestion and moderate glucose absorption. They also promote satiety, making it easier to maintain healthy eating patterns without constant hunger and cravings.

Protein recommendations vary widely depending on age, activity level, health status, and goals. The Recommended Dietary Allowance (RDA) suggests a minimum of 0.8 grams per kilogram of body weight daily, but many nutrition experts suggest higher intakes ranging from 1.2-2.0 g/kg for active people or those looking to preserve muscle mass with aging. Research shows that distributing protein intake throughout the day, rather than consuming most of it at dinner (as is common in Western diets), may be more beneficial for muscle protein synthesis and overall health. Most people should aim for 25-30 g per meal.

Protein helps preserve and build muscle mass, which is crucial for health as we age. Protein-rich foods also stimulate the release of hormones that slow gastric emptying and promote fullness. Good sources include meat, poultry, fish, eggs, dairy, legumes, and, to a lesser extent, nuts and seeds.

For fiber, recommendations range from the basic 25-30 grams suggested by most health organizations to as much as 50 grams recommended by some experts for optimal digestive and metabolic health. The average American consumes only 10-15 grams daily. Fiber feeds beneficial gut bacteria, which produce short-chain fatty acids that reduce inflammation. It also forms a physical barrier that slows carbohydrate absorption in the small intestine. Excellent fiber sources include vegetables, fruits (especially berries), legumes, nuts, seeds, and whole grains.

When planning meals, think of protein and fiber as non-negotiable components. Even when including carbohydrates in a meal, pairing them with protein and fiber can help moderate their impact on blood glucose and insulin.

How much protein do I need, and how do I get enough?

The benefits of fiber: Why fiber is essential to metabolic health

13 High-fiber meals and snacks for better blood sugar

4. Include healthy fats in your diet

Don’t fear fat, but be mindful of quality and choose primarily unsaturated fats with some saturated fats from whole food sources.

Fat has been unfairly villainized in past decades, but we now understand that the type and quality of fat matter far more than the total amount. Healthy fats are essential for hormone production, nutrient absorption, cell membrane integrity, and brain health. They also help slow digestion, supporting stable blood sugar and insulin levels.

Focus on monounsaturated fats like those found in olive oil, avocados, and nuts, which have been linked to reduced inflammation and improved health markers. Multiple large-scale studies, particularly those examining Mediterranean-style diets, have found benefits of diets rich in these fats for cardiovascular health, cognitive function, and overall longevity.

Omega-3 fatty acids, found in fatty fish, flaxseeds, and walnuts, are particularly beneficial for health. They reduce inflammation and support cardiovascular function. However, many Americans consume too few omega-3s and too many omega-6 fatty acids (common in processed foods and some vegetable oils), creating an imbalanced ratio that may promote inflammation.

The science on saturated fats continues to evolve. Current evidence suggests that saturated fats from whole, minimally processed foods like eggs, grass-fed meat, and dark chocolate may not carry the cardiovascular risks once attributed to them, especially when consumed as part of an overall healthy diet. Context matters—the impact of saturated fat appears to depend on the specific food source, an individual’s overall diet quality, and genetic factors.

When cooking or preparing foods, use minimally processed fats and oils like extra virgin olive oil, avocado oil, and small amounts of grass-fed butter or ghee rather than highly refined options.

Why omega 3s are crucial to strong metabolic health

5. Be thoughtful about cooking oils

Choose minimally processed oils for cooking and flavoring foods, and be cautious about industrial seed oils.

The oils you use for cooking and food preparation can significantly impact your health. While the research in this area continues to evolve, several principles are worth considering.

Extra virgin olive oil is one of the most well-studied cooking oils, with extensive research supporting its health benefits. It’s rich in monounsaturated fats and contains numerous beneficial compounds, including polyphenols, which have antioxidant and anti-inflammatory properties. Extensive, long-term studies consistently show that higher consumption of olive oil is associated with reduced risk of cardiovascular disease, certain cancers, and overall mortality.

Other minimally processed oils with potential health benefits include avocado oil and small amounts of coconut oil (though the latter is high in saturated fat). These oils are extracted using methods that preserve their natural compounds and don’t require extensive industrial processing.

More controversial are industrial seed oils, including soybean, corn, cottonseed, canola, safflower, and sunflower. These oils became widespread in the American diet only in the last century, coinciding with the rise of industrial food production. They require extensive processing with heat and chemicals to extract, which may degrade their nutritional quality. Some research suggests that high omega-6 polyunsaturated fats in these oils may contribute to inflammation when consumed in large amounts, though this remains debated among nutrition scientists.

The evidence regarding seed oils’ health effects is mixed and still evolving. While some observational studies suggest potential benefits when replacing saturated fats, other research raises concerns about their oxidative stability, especially when heated to high temperatures for cooking. The high omega-6 to omega-3 ratio in these oils may also be problematic when consumed in large quantities.

Given the uncertainty, a reasonable approach is to prioritize oils with more substantial evidence of health benefits (like extra virgin olive oil) for everyday use while being mindful of the quantity and quality of more processed oils in your diet, particularly those found in ultra-processed foods.

What to know about cooking with fats and oils

6. Make smart choices about grains, starches, and carbs

Choose whole, intact grains and starches over refined versions, and pair them with protein, fat, and fiber.

Popular diet culture often unfairly demonizes carbohydrates, but the quality, quantity, and context of your carb consumption matter far more than simply eliminating them. Numerous healthy populations worldwide consume moderate amounts of carbohydrates, particularly from whole food sources. Carbs are also a source of energy for exercise.

When choosing carbohydrate-rich foods, opt for those that remain as close to their natural state as possible. For example, intact whole grains like quinoa and bulgur generally impact blood sugar and insulin less than processed grain products, even those labeled “whole grain.” The degree of processing and particle size significantly affect how quickly carbohydrates are digested and absorbed.

Similarly, starchy vegetables like sweet potatoes, squash, and legumes provide carbohydrates along with fiber, vitamins, minerals, and other beneficial compounds. These foods generally have a more moderate effect on blood sugar and insulin than refined grains and added sugars, especially when consumed as part of a mixed meal with protein and healthy fats.

Some experts recommend looking at a food’s carbohydrate-to-fiber ratio, aiming for a ratio of less than 5:1. For example, a food with 15g of carbs should have at least 3g of fiber to meet this threshold. This helps ensure you’re getting adequate fiber with your carbohydrates.

Some carbohydrate-rich foods also contain resistant starch, which resists digestion in the small intestine and ferments in the large intestine, feeding beneficial gut bacteria. Foods high in resistant starch include unripe bananas, cooked and cooled potatoes and rice, and legumes. Multiple studies indicate that resistant starch may improve insulin sensitivity and gut health.

Non-starchy vegetables (like leafy greens, broccoli, and peppers) are excellent sources of nutrients and fiber with minimal impact on blood sugar and insulin, making them essential to any healthy eating pattern.

Read more:

12 Healthy ways to eat carbs

What is resistant starch and how does it impact glucose?

Are “whole grain” and “whole wheat” products healthy?

7. Consume dairy thoughtfully

Choose high-quality dairy sources or alternatives based on your tolerance and preferences.

Dairy products can be part of a healthy diet for many people, offering protein, calcium, vitamin D, and other nutrients. However, dairy’s impact varies widely among people, making it a food category that calls for personalized decisions.

Dairy products, particularly fermented ones like yogurt and kefir, can provide beneficial probiotics for gut health. Multiple studies have found associations between fermented dairy consumption, improved gut microbiota diversity, and reduced markers of inflammation. Fermentation creates short-chain fatty acids and other compounds that may benefit metabolic health.

However, dairy can trigger a disproportionately high insulin response relative to its carbohydrate content. This exaggerated insulin response could be problematic for some, particularly those with insulin resistance. Additionally, a notable portion of the world’s population has some degree of lactose intolerance, and others may have sensitivity to milk proteins.

Extensive observational studies generally show neutral or slightly beneficial associations between dairy consumption and cardiovascular disease, with fermented dairy products often showing the most favorable outcomes. While some earlier research raised concerns about saturated fat in full-fat dairy, more recent evidence suggests that dairy fat may have a neutral or protective effect on many people's health.

If you choose to include dairy in your diet, consider the following:

Opt for full-fat dairy products rather than low-fat or fat-free versions, as the fat helps moderate glucose response and provides fat-soluble vitamins.
Prioritize fermented dairy like unsweetened yogurt and kefir for their probiotic benefits.
Choose high-protein options like Greek yogurt, cottage cheese, or aged cheeses, which provide more protein per serving.
When possible, consider organic or grass-fed sources, as they may contain higher levels of beneficial nutrients like omega-3 fatty acids and conjugated linoleic acid (CLA).
If you are sensitive to dairy, consider A2 milks. They contain a different kind of protein that some evidence suggests can cause fewer digestive problems in sensitive individuals.

If you’re lactose intolerant or choose not to consume dairy, numerous plant-based alternatives are available. When selecting these, opt for unsweetened versions. Be aware that many contain additives and may not provide the same nutrient profile as dairy. Fortified options can help ensure adequate calcium and vitamin D intake.

The best milk alternatives for better blood sugar

8. Eat for micronutrient density and variety

Maximize micronutrients by eating a diverse range of colorful plant foods and high-quality animal products.

While macronutrients (protein, fat, and carbohydrates) often get most of the attention, micronutrients—vitamins, minerals, and phytonutrients—are equally crucial for optimal health. These compounds are cofactors for countless metabolic processes, support immune function, and help regulate cellular health.

Aim to incorporate various plant foods in your diet each week. Research suggests that greater dietary diversity, particularly of plant foods, is associated with lower risks of chronic diseases and better overall health outcomes. While some experts recommend as many as 30 different plant foods weekly, any increase in the diversity of fruits, vegetables, nuts, seeds, and legumes in your diet is beneficial. In short, keep pushing yourself to add new foods to your diet to ensure micronutrient diversity.

Different colored fruits and vegetables contain other beneficial compounds, so “eating the rainbow” ensures you get a broad spectrum of nutrients. For example, red and orange produce contains lycopene and beta-carotene, while purple and blue foods are rich in anthocyanins.

Animal foods like organ meats, seafood, eggs, and dairy products are also excellent sources of certain micronutrients that are difficult to obtain from plant sources alone, including vitamin B12, heme iron, zinc, and certain forms of vitamin A and omega-3 fatty acids. Including some high-quality animal foods in your diet can help ensure adequate intake of these nutrients.

Several large-scale systematic reviews and meta-analyses have found that higher intakes of fruits and vegetables—foods rich in various micronutrients—are associated with reduced risk of cardiovascular disease, certain cancers, and all-cause mortality. The protective effects appear to be related not just to fiber content but also to the diverse array of vitamins, minerals, and phytonutrients these foods contain.

Even with a nutrient-dense diet, some people may benefit from targeted supplementation, particularly vitamin D, magnesium, and omega-3s, which many Americans lack. However, getting nutrients from whole foods is generally preferable, as food provides nutrients in natural ratios and with complementary compounds that enhance absorption and utilization. Supplements remain loosely regulated, making them a less reliable source of nutrients.

Read more:

The Magic of Micronutrients

8 Micronutrients essential for metabolic health

9. Hydrate adequately and be mindful of what you drink

Focus on water as your primary beverage, and be cautious with juices, alcohol, and artificially sweetened drinks.

We’ve all heard that you should drink more water—generally true—but what you drink can also significantly impact your health. Water should be your go-to beverage—it supports all bodily functions and helps maintain proper hydration without adding calories or triggering blood sugar and insulin responses.

Fruit juices, even those without added sugar, can negatively affect metabolic health due to their concentrated sugar content and lack of fiber. A single glass of orange juice contains the sugar of several oranges but none of the fiber that would typically slow sugar absorption. Similarly, sweetened beverages like soda deliver enormous amounts of rapidly absorbed sugar with no nutritional value.

Multiple large prospective cohort studies and meta-analyses have found strong associations between sugar-sweetened beverage consumption and increased risk of Type 2 diabetes, obesity, cardiovascular disease, and other chronic conditions. Even fruit juice consumption has been linked to increased health risks in some studies, though to a lesser extent than sodas and other sweetened drinks.

Be cautious with alcohol, which can impact health through multiple mechanisms. Alcoholic beverages often contain carbohydrates, and alcohol itself is prioritized for metabolism in the liver, potentially leading to increased fat storage and impaired glucose regulation. Large-scale epidemiological studies suggest that even moderate alcohol consumption may carry health risks, challenging the notion that moderate drinking is beneficial.

Artificially sweetened beverages aren’t necessarily better alternatives. Some studies indicate that despite containing no calories, artificial sweeteners may negatively affect the gut microbiome and potentially contribute to glucose intolerance and insulin resistance. However, research in this area is still evolving.

Coffee and tea, particularly when unsweetened, can benefit health due to their polyphenol content, which may improve insulin sensitivity and reduce inflammation. Multiple extensive observational studies have found associations between moderate coffee and tea consumption and reduced risk of various chronic diseases.

13 Soda alternatives less likely to spike your blood sugar

The 12 best non-alcoholic and low-carb beers

10. Adapt to your individual responses

Recognize that responses to food are highly individual; pay attention to how different foods make you feel.

One of the most important principles of good nutrition is the understanding that different people can respond dramatically differently to the same foods. Just because your friend loved going keto doesn’t mean it’ll work for you. Various factors, including genetics, gut microbiome composition, physical activity, sleep quality, stress levels, and existing health conditions, can all influence how your body processes different foods.

Multiple large-scale studies have demonstrated significant interpersonal variability in responses to identical meals, particularly regarding glucose, insulin, and blood lipid responses. This suggests that standard dietary recommendations may not work equally well for everyone. A food that causes digestive issues, energy crashes, or inflammatory symptoms in one person might have minimal impact on another.

While specialized testing can provide insights into individual responses, you can gain valuable information simply by paying attention to how different foods make you feel. Energy crashes, increased hunger, or cravings shortly after eating may indicate a blood sugar and insulin issue. Digestive discomfort might signal food sensitivities. Mental fog, joint pain, or skin problems could be related to inflammatory responses to certain foods.

Consider keeping a food journal or logging meals in an app for a few weeks, noting not just what you eat but how you feel afterward. This simple practice can reveal patterns and help you customize these dietary guidelines to your unique physiology. Try experimenting with different meal compositions, timing, and portion sizes to find what works best for your body.

Remember that your nutritional needs and responses may change over time due to factors like aging, activity levels, health status, and life circumstances. Regular reassessment and adjustment of your dietary patterns may be necessary.

11. Be skeptical of extreme claims and quick fixes

Focus on sustainable, evidence-based approaches rather than chasing the latest nutrition trends.

Nutrition science is complex and constantly evolving, which unfortunately creates fertile ground for oversimplified answers, extreme ideologies, and “silver bullet” solutions. While seeking clear answers in a confusing landscape is natural, be wary of any approach that promises dramatic results through a single change, demonizes entire food groups, or claims to have discovered the One True Cause of modern maladies.

Health influencers, popular books, and media headlines often promote nutrition advice based on cherry-picked studies, anecdotal evidence, or incomplete science. These approaches may work for some people in the short term but rarely translate to sustainable, long-term health improvements for most.

Instead, start by identifying the highest-impact changes for your situation. For many, eliminating added sugars and ultra-processed foods offers substantial health benefits with relatively few behavioral changes. From there, gradually incorporate other principles as they become sustainable habits. Research shows that habits are more likely to stick when integrated slowly and built upon existing routines. And studies on successful long-term weight management have found that sustainable approaches that allow flexibility tend to be more successful than rigid diets. Consistent small changes, rather than drastic overhauls, typically lead to better long-term outcomes.

Understand that nutrition is just one aspect of health. Sleep quality, physical activity, stress management, social connections, and other lifestyle factors are crucial in overall well-being. A moderate approach to nutrition that allows for flexibility and enjoyment is more likely to support these other aspects of health than a highly restrictive diet that creates stress and social isolation.

Finally, remember that perfection isn’t necessary for progress. Even minor improvements in dietary quality can yield meaningful health benefits. The goal is to develop a sustainable approach to eating that supports your health while allowing flexibility for life’s realities.

The 2024 Levels Guide to Metabolic Health Interventions

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