When it comes to nutrition and chronic disease, focus on the basics

Never mind the fad diets, it really just comes down to what you eat and drink regularly, says a team of UCLA Health scientists

Over the last century, the medical community’s understanding of dietary science and the role of nutrition in the development of chronic diseases has expanded dramatically. However, so-called “fad diets” and poor health advice from non-experts – fueled by social media – has led to the rapid growth of misinformation.

To combat this epidemic of health misinformation, it is helpful to refocus on the basics: what to eat and drink.

Simple and manageable adjustments to diet and beverage choice can result in dramatic improvements in health. They can also serve as preventive measures against silent killers such as obesity, hypertension – elevated blood pressure – and diabetes, protecting the health of main organs such as the brain, eyes, heart and kidneys, and increasing life span.

Following are the most up to date best practices for food and fluid intake, backed by research and established scientific data, for the promotion of overall wellness and chronic disease prevention.

Food prepared by Dr. Niloofar Nobakht. (Photo by Safa Shahidi) 

Dietary trends

Although nutritional intake in the United States has improved in recent years, the population is still largely falling short of recommended nutritional guidelines. Notably, people do not consume enough vegetables, whole grains and fatty acids, and they eat too many empty calories and salty meals.

The association between diet and cardiovascular disease in the United States is well known; in particular, diets high in sodium and low in vegetables, whole grains and fatty acids are most strongly associated with hypertension, cardiovascular disease, stroke and type 2 diabetes. High-sodium diets, in particular, are most predictive of mortality due to cardiometabolic disease.

These trends and associations are concerning from a public health standpoint, as increasing lifestyle-related illnesses could eventually overburden the U.S. health care system.

Salt (sodium and potassium)

Sodium and potassium exist in a variety of foods, and their imbalance can lead to adverse effects on major end organs such as the brain, eyes, heart and kidneys. Sodium and potassium assist with fluid and blood volume maintenance and, therefore, impact blood pressure in contrasting ways: excess sodium and low potassium intake can increase blood pressure.

For those with abnormal kidney function, high potassium intake may pose a health risk, and these individuals should consult with their nephrologist before modifying their diets.

Management of blood pressure is crucial to decrease end organ damage and mortality. As of 2021, the most recent public health guidelines indicate that hypertension can be diagnosed when blood pressure is 130/80 or greater. Only about 25% of adults in the United States have their blood pressure under control.

For healthy individuals with normal kidney function, a diet abundant in potassium is optimal. Due to its role in reducing blood pressure, potassium is an essential electrolyte for promoting cardiovascular health and preventing end organ damage. Diets high in potassium also are linked to a reduction in risk for stroke.

Dr. Niloofar Nobakht

Since potassium reduces excretion of calcium, high potassium diets also are beneficial for the prevention of conditions such as osteoporosis and kidney stones.

The average diet in the United States contains an excess of sodium and a dearth of potassium; most people barely achieve half of the recommended daily intake for potassium. The best sources of dietary potassium include apricots, bananas, prunes, cantaloupes, squash, potatoes and lentils.

Consumption of more than 2 grams of sodium per day has been strongly associated with mortality due to cardiovascular conditions. Globally, more than 88% of adults exceed the recommended daily intake of 2 grams of sodium by at least 1 gram.

Excess dietary sodium can come from surprising sources. Beyond the expected culprits of processed food, meats and pre-packaged meals, which can be part of weight-loss plan packages, unexpected sources of sodium – hidden salt – can be found in store-bought bread, chicken, cheese and restaurant-cooked meals. Given the inextricable link between dietary sodium and the development of chronic illness such as heart and kidney disease, hypertension and stroke, switching to lower-salt meals can assist with reaching and maintaining normal blood pressure and decreasing morbidity and mortality.

Dr. Mohammad Kamgar

One of the best diet plans, backed by well-designed and well-executed scientific clinical trials, is the DASH (Dietary Approaches to Stop Hypertension) diet.

The DASH diet is based on weekly nutrition goals as opposed to prescribing specific foods or meals. It makes several recommendations for nutrients and food groups to consume moderately and includes minimizing foods with added sugars, saturated fats and trans fats, and opting for lower-sodium options. It encourages followers to eat more nutrient-dense foods, particularly those high in fiber, protein, and mineral nutrients such as potassium, calcium and magnesium. DASH recommends increasing the consumption of whole grains and vegetables and incorporating dense foods such as nuts, legumes, lean proteins, fish and low-fat dairy products into your diet.

It can highly benefit the improvement of overall health and wellness, regardless of pre-existing conditions or risk level for chronic diseases. Studies have found that adherence to the DASH diet not only improves blood pressure, but can lead to healthy weight loss, improve insulin metabolism, reduce inflammatory markers and reduce triglycerides.

Owing to its flexibility, efficacy and ability to be applied to the cuisine of any culture, the principles outlined in DASH can be useful for all wellness-minded individuals. Learn more about the DASH diet.

Sugar (carbohydrates and glucose)

Noor Jahanshahi

There is a lot of confusion in the public sphere regarding sugar and carbohydrates and whether these two are different or the same. Neither train of thought is completely correct: Sugars are, in fact, a type of carbohydrate.

Carbohydrates are a major macronutrient and are essential for human health. They are most easily ingested and converted to glucose, which is the essential energy source for all cells of the body. After carbohydrate ingestion, blood glucose increases and the pancreas responds by releasing insulin, which allows glucose to enter the cells of the brain, liver, muscles and adipose tissue to be used as energy.

In the adult brain, neurons have the highest energy demand and need a continuous delivery of glucose from the bloodstream. In humans, the brain accounts for around 2% of body weight, but it consumes approximately 20% of glucose-derived energy, making it the main consumer of glucose (roughly 5.6 milligrams glucose per 100 grams human brain tissue per minute).

Excess insulin in the bloodstream may lead to insulin resistance, and to a vicious cycle in which the pancreas repeatedly releases insulin to elicit a response from the resistant cells and blood glucose remains high. This can lead to abnormal blood glucose, prediabetes and later type 2 diabetes.

Development of type 2 diabetes can lead to other serious health problems, most notably damaging of vascular organs such as eyes, heart and kidneys, as well as peripheral vascular disease. In the United States, only 12% of adults are fully metabolically healthy; this means that 88% of the population are at significant risk for developing chronic illness, cardiovascular disease and compromised organ health.

Per the Centers for Disease Control and Prevention – 2020 National Diabetes Statistics report – 13% of the U.S. population age 18 and older have diabetes, 34.5% of adults have prediabetes and 33% of diabetic adults develop chronic kidney disease.

High sugar and refined carbohydrate intake are established causes of poor health and chronic illnesses such as type 2 diabetes, obesity and various metabolic syndromes. Diets high in both saturated fat and sugar can even increase the risk of kidney and liver diseases. Added sugars, in contrast to naturally occurring sugars, have been identified as leading culprits for the development of diet-related poor health.

Leading sources of excess added sugars in the American diet include sweetened beverages (such as sodas), fructose syrups and sugary snacks.

It is important to note that artificial sweeteners are not as healthy a substitute for refined sugar as once believed: Studies have shown that consumption of artificial sugars is associated with obesity, insulin resistance and changes in gut microbiota. As such, refined and artificial sugars should be avoided or minimized to promote wellness.

Plant-based vs. animal-sourced diets

Another dietary change that could be beneficial, especially for those with chronic illnesses, is to increase plant-based meals.

Plant-based diets are high in vegetables and whole grains and minimize or eliminate proteins and fats derived from animals. Fats and proteins instead come from oils, nuts, seeds and legumes.

It is important to note that simply being labeled “vegan” or “vegetarian” is not indicative of a food’s health benefits. Oreo cookies, for example, are vegan, but are obviously a less healthy source of sugar and starch than fresh fruit.

A balanced plant-based diet that does not overly rely on carbohydrates and processed foods is optimal for health. In fact, evidence shows that unhealthy plant-based diets can increase the risk for both total and cardiovascular mortality, whereas healthy, high-quality plant-based diets lower the risk of both.

Plant-based diets have been shown to be beneficial for those with chronic kidney disease (CKD) and may even be preventive against CKD for those at risk. Plant-based diets offer a low-risk, nutrient-dense alternative for kidney patients who may be adversely affected by diets high in animal proteins. Combining the DASH diet and a plant-based lifestyle may produce significant benefits for patients with CKD, as studies have shown this combination may slow disease progression and improve overall survival.

Anecdotal evidence also demonstrates that plant-based diets may help to improve pain and symptoms in those with neurological and rheumatological disorders. Patients with these disorders were shown to have reduced antibodies and disease markers after adopting plant-based eating.

Water intake for wellness

Hand-in-hand with a proper diet, water intake and hydration play an important role in wellness. Water intake is essential for homeostasis and the continuation of metabolic functions.

Adequate water intake can vary depending on age, gender, activity level and pre-existing conditions. General guidelines recommend that adult men consume about 13 cups of water and adult women about 9 cups of water per day. For all individuals, hydration needs generally increase during and following exercise. For women, this need increases during pregnancy and breastfeeding.

Many beverage companies make sensational claims about the ability of their beverages to compete with water as a source of hydration. Everything from sweetened electrolyte drinks to coconut water and even soda has been peddled at some point as a worthy substitute for water. Consider, however, that such drinks may provide more electrolytes than plain water, or might contain unnecessary calories and added sugars, or may have artificial sweeteners.

Infused water is a healthy and tasty alternative to plain water and flavored drinks. Infused fresh water can be made by placing sliced citrus or herbs in a receptacle of water and allowing the flavor to dissipate. This is an excellent method for unenthusiastic water drinkers to make hydration more feasible.

Coffee and tea

There are conflicting claims about the risks and benefits of caffeinated beverages, specifically coffee and tea.

When consumed in moderation, coffee and tea pose little to no health risks for healthy individuals. Contrary to common belief, moderate consumption of coffee does not produce a dehydrating effect. While coffee consumption can produce a slight diuretic effect, this is not significant enough to be of concern in healthy individuals who drink less than two cups per day. Studies have found that consuming as much as four cups of coffee in a day does not produce significant dehydration.

Tea consumption is of even less concern. Regular consumption of black, green, oolong or white tea has been associated with reduced risk of stroke, type 2 diabetes and heart disease.

That said, it is important to be careful that daily cups of tea or coffee do not become vessels for excess sugar, fat and calories through the addition of syrups, sweeteners and creamers.

Fruit juice or soda

Sugar-laden drinks such as carbonated soft drinks and fruit juices pose a large risk for general health. The CDC recommends that drinks sweetened with sugar be avoided, if not eliminated, as their regular consumption is associated with the development of obesity; type 2 diabetes; kidney, liver and cardiovascular disease; as well as dental problems.

Fruit juices that do not contain added sugars (100% juice beverages) may be consumed in small amounts from time to time, but consumers should be aware that sugar from fruit still spikes blood glucose just as sugar from other sources.


Alcoholic beverages may also have negative health impacts. Furthermore, emerging research suggests that higher alcohol intake may be associated with hypertension and cardiovascular disease.

Long-term excessive alcohol use also has a tremendous impact on the health of major organ systems, leading to cognitive decline and mental health problems, and increasing the risk of stroke and liver failure. Alcohol consumption affects the kidney by producing a diuretic effect, which promotes water loss through urine and inhibits vasopressin, a hormone which can cause dehydration in some cases based on percentage and volume of alcohol.

Best nutrition practice to improve health and wellness

Simple strategies such as reducing sodium intake and minimizing consumption of added refined sugars and saturated fat can help prevent diet-associated illnesses and promote overall wellness. However, individuals with medical conditions such as diabetes, hypertension, and heart and kidney disease may benefit from more specific recommendations and guidelines that directly address the existing ailments. We recommend the DASH diet, which supports long-term lifestyle changes and adopting a lower glycemic index, among other practices.

As far as beverage choice, the best practice for the promotion of wellness is to minimize the consumption of sugar-laden drinks and alcohol to two drinks or less in a day for men or one drink or less per day for women. To encourage water consumption, obtaining a vacuum insulation bottle free of BPA, plastic and contaminants makes access to fresh water or homemade fruit-perfused fresh water simpler and more cost effective than purchasing water.

It is harder to combat unhealthy habits built over time, so educating children on simple lifestyle strategies will be key to their future health and wellness.

Niloofar Nobakht, MD; Mohammad Kamgar, MD; and Noor Jahanshahi are the authors of this article. Dr. Nobakht and Dr. Kamgar are faculty nephrologists with the UCLA Department of Medicine; Noor is an administrative assistant at UCLA.