The 6 Dietary Tips Patients Need to Hear From Their Clinicians

The research is out: diet matters. Here's what patients need to know.

Naveed Saleh, MD, MS; Reviewer: Renee Simon, MS, CDN, CNS


June 29, 2017

The constant barrage of diet and nutrition information that is published can make it difficult for clinicians to separate the wheat from the chaff when counseling patients, but research tells us that nutrition is a critical component to human health. Here are six evidence-based tips that are easily shared with patients.

1. Choose foods with a wide variety of colors and textures, in their most natural forms. Foods that are enjoyed in a natural state provide the greatest satiety and nutritional value.

Even if patients hear nothing else their clinician tells them, choosing a wide variety of unprocessed colors and textures—foods as close to their original, natural states as possible—will make the most significant difference in long-term health and longevity.

7.4% of all cardiometabolic deaths were linked to sugar-sweetened beverages, and 8.2% were linked to processed meats.

Results from a March 2017 JAMA study by Micha and colleagues[1] indicate that nearly one half of all cardiometabolic deaths (ie, 318,656 of 702,308 such deaths) in the United States "were associated with suboptimal intakes" of vegetables, fruits, nuts, and seeds, as well as omega-3 fatty acids. "Cardiometabolic death" refers to death from heart disease, stroke, and type 2 diabetes.

Among their guideposts for healthy eating, the American Heart Association (AHA) promotes consumption of an array of nuts, seeds, legumes, fruits, and vegetables. The AHA recommends that at least one half of the plate be filled with fruits and vegetables. A variety of vegetables adds color to any plate and refreshment to any palate.[2] Although some people find it difficult to consume large quantities of a single vegetable, many find that combining a variety of selections makes vegetables more palatable.

2. Avoid or dramatically minimize processed foods. Processed foods and beverages, such as packaged snacks, smoked meats, white flour, and sugar-sweetened foods and beverages, should be eschewed.

Micha and colleagues[1] found that 7.4% of all cardiometabolic deaths were linked to sugar-sweetened beverages, and 8.2% were linked to processed meats. Salt showed similar negative correlations.

Many nutritionists and clinicians are concerned about blood glucose levels, obesity, diabetes, and other health implications, and they believe that sugar is the "new tobacco." At the same time, recent studies show that artificial sweeteners and diet soda may not be protective, and may even do harm.

Sodium is another long-time concern, and is prevalent in processed foods. As reported in Medscape Medical News, "By far, most of the sodium Americans ingest—nearly 71%—comes from foods prepared outside the home, new research indicates." The article points out that the sodium naturally occurring in whole foods is rarely substantial.

The take-away message is that people should prepare most of their own meals, especially avoiding packaged foods. Amidst these concerns, the FDA will soon be rolling out new dietary guidelines that will give patients a better idea of what exactly they are eating.

3. Choose realistic, balanced diets for weight loss and weight maintenance. The most successful diet is one that patients can stick to. Plenty of diets have proven effective for weight loss and weight maintenance. When dieters fail, it is because they attempt to follow diets that are too restrictive; are unbalanced; or cause rapid weight loss, which leads to yo-yo dieting.

Depending on the patient, clinicians can recommend the Mediterranean diet, portion-control plates or Weight Watchers, and even intermittent fasting. Diets with certain characteristics promote weight loss and weight maintenance[3]:

  • Increased vegetable and fruit intake;

  • Consumption of foods that are high in fiber;

  • Consumption of whole-grain foods;

  • Increased water intake;

  • Decreased intake of dietary sugar (eg, sugar-sweetened beverages);

  • Sufficient protein intake; and

  • Sufficient intake of healthy fats.

Diets that are low in carbohydrates and high in protein result in greater weight loss over a given period than calorically equivalent diets that contain relatively more carbohydrates.[3] Patients who prefer higher-carbohydrate options, such as the Pritkin diet, can still lose weight at a slower pace.

One helpful rule of thumb is one half a plate of vegetables, one fourth a plate of lean protein, and one fourth a plate of high-fiber complex carbs, plus one serving of healthy fat.

Low-fat diets are more effective when they include high-protein over standard-protein intake.[3] However, not all fats should be avoided, and low fat is no longer gets the gold star. Whereas saturated fat leads to unhealthy levels of blood lipids, there is significant evidence that diets high in healthy fats can be effective, and can be recommended as long as they include high-quality protein, fiber, and produce as well.

Specific diets that have proven effective at weight loss plus reduction in body mass index include the DASH diet, Mediterranean diet, Nutrisystem, Weight Watchers, and Jenny Craig. The Mediterranean diet is heavy in vegetables, fruits, nuts, fish, whole grains, and healthy unsaturated fats (found in olive, avocado, and other plant oils).[3]

Portion-control plates promote weight loss and maintenance across the board, including in patients struggling with obesity and type 2 diabetes.[3] One helpful rule of thumb is one half a plate of vegetables, one fourth a plate of lean protein, and one fourth a plate of high-fiber complex carbs, plus one serving of healthy fat.

In the past, dieting advice often suggested grazing throughout the day, because going long periods without food was frowned upon. If patients want to practice intermittent fasting, however, the evidence now shows that this can be safe and effective. Preliminary research indicates that some forms of alternate-day fasting may result in weight loss and lowered cardiovascular risk.[4,5]

Although one recent study found no benefit to fasting other studies indicate that intermittent fasting yields weight loss similar to that achieved with continuous caloric restriction. It can be inferred from the results of these other clinical studies that intermittent fasting could serve as an alternative to standard diets that restrict caloric intake.[4] From a practical standpoint, not everyone can withstand long periods without food. However, patients who prefer to eat larger but less frequent meals can try a modified strategy of limiting food intake to an 8-hour period each day, then fasting for 16 hours in between.

4. Consume healthy oils for heart health: fish, olive, avocado. Fish oils can prevent further illness in those with a history of heart disease. The AHA recommends that everybody eat fish that are rich in omega-3 fatty acids.[2] Other beneficial fats include olive oil, avocado oil, canola oil, walnut oil, flaxseed oil, and chia seed oil.

7.8% of cardiometabolic deaths were tied to low levels of omega-3 fatty acids in the diet.

Although understanding the complex interplay between good fats and bad fats is an ongoing challenge, certain fats and oils are known to have benefits; these include fish oil and olive oil.

Micha and colleagues[1] found that in 2012, 7.8% of cardiometabolic deaths were tied to low levels of omega-3 fatty acids in the diet.[1] Salmon, mackerel, and certain other fish are high in omega-3 fatty acids. Although fish oils, which contain eicosapentaenoic acid and docosahexaenoic acid, are considered the ideal source,[6] vegetarian and vegan patients can use flaxseed, walnut, or chia seed oils, which contain alpha-linolenic acid, a precursor to the omega-3s. Consumption of fish itself is always the optimal choice, but fish oil supplements are also available over the counter. Many randomized controlled trials (RCTs) have analyzed supplementation with fish oils or omega-3 polyunsaturated fatty acids. In April 2017, the American Heart Association reviewed fish-oil studies and issued an AHA science advisory. According to the AHA[7]:

Although recent RCT evidence has raised questions about the benefits of omega-3 supplementation to prevent clinical CVD [cardiovascular disease] events, the recommendation for patients with prevalent CHD [coronary heart disease] such as a recent MI remains essentially unchanged: Treatment with omega-3 PUFA [polyunsaturated fatty acid] supplements is reasonable for these patients. Even a potential modest reduction in CHD mortality (10%) in this clinical population would justify treatment with a relatively safe therapy.

Research has also found that vitamin D works in conjunction with the omega-3s to improve cognitive function and social behavior, as well as overall mood.[8]

5. Forego red meat and live longer. Although red meat is a principal source of protein and fat, research shows that consumption of red meat is linked to increased risks for cancer, diabetes, and cardiovascular disease, all of which decrease longevity.

In a 2012 study titled "Red Meat Consumption and Mortality: Results from Two Prospective Cohort Studies," Pan and colleagues[9] prospectively followed 37,698 men and 83,644 women, all of whom were health professionals, during a maximum period of 28 years. These participants did not have cardiovascular disease or cancer at baseline. The researchers found that consumption of red meat increased risk for cardiovascular, cancer, and total mortality.

The researchers also found that substituting one serving of red meat per day with one serving of fish, poultry, legumes, nuts, whole grains, and low-fat dairy was associated with a 7%-19% reduction in mortality risk. Moreover, if participants consumed less than one half a serving of meat per day (< 42 g), then 9.3% of deaths in men and 7.6% of deaths in women could have been prevented.

More recent research has shown that red meat consumption is correlated with a risk of dying of many diseases.

6. Consume fermented foods/probiotics and fiber for gastrointestinal and overall health. Probiotics contain microorganisms that confer gastrointestinal benefit. They are commonly found in yogurt, kefir, and unpasteurized fermented foods and drinks. They can also be taken in supplement form. In order to thrive, probiotics require prebiotics as food, which can be found in fiber.

Probiotics contain nonpathogenic yeast and bacteria that lower intestinal pH, decrease the invasion of pathogenic organisms in the gut, and modify immune response.[10] The human microbiome has been implicated in a wide variety of health and disease states. An extensive body of research is still exploring how that research can be made translational for several conditions, but for now, probiotics have definitely been found to benefit gut health.[10]

[R]ecommending high-quality fermented and cultured foods, along with whole grains and other fiber-rich foods, is a very good idea.

In a 2010 clinical review on probiotics, Williams[10] stated, "The strongest evidence for the clinical effectiveness of probiotics has been in the treatment of acute diarrhea, most commonly due to rotavirus, and pouchitis."

One recent study found that indolepropionic acid, a metabolite produced by intestinal bacteria and fortified by a fiber-rich diet, is protective against type 2 diabetes, whereas another study found a protective link against colon cancer. Research into the microbiome/mental health connection has also been intriguing.

Although this is still a very young research area, the results are promising enough that recommending high-quality fermented and cultured foods, along with whole grains and other fiber-rich foods, is a very good idea.

It is said that human beings can only remember four things at once. Anecdotal evidence has suggested seven. Above, there are six key pieces of nutritional advice that most every patient could benefit from.

Should a patient with an extraordinary memory manifest, physicians can add two more bits of related advice to the nutrition list: Avoid alcohol, or limit consumption to one drink per day for women or two for men; and try not to substitute food sources with vitamin supplements. Alcohol has been linked to several conditions and diseases, including seven cancers. And although supplements may not cause harm, they could potentially make patients a bit more lax in terms of trying to eat a healthful diet, and evidence that supplements can replace genuine nutrition is scarce.[11,12]

Traditionally, physicians have focused on clinical treatments, leaving matters of diet to the registered dietitians and nutritionists. With an unwieldy amount of diet advice being bandied around on a regular basis, some might be tempted to stay clear of this domain. Because evidence is mounting that diet plays a significant role in health and disease, though, it is important that each clinician remind patients of the most important dietary tips they should be following. With enough reinforcement, it could make a difference.


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