How bad are carbs, really?

 

There is a fear that carbohydrates are detrimental to health. As a result, low carb diets have become popular, especially for weight loss. In this Honest Nutrition feature, we explain what carbohydrates are, look at healthy vs. unhealthy options, and discuss whether a diet rich in carbs is actually harmful.

Carbohydrates are one of the three macronutrients that occur naturally in plant foods, including peas and beans, nuts and seeds, grains, dairy and dairy products, fruits, and vegetables.

The other two macronutrients are dietary fats and proteins.

Carbohydrates are considered essential nutrients for the body to function properly by several global health organizations, including the World Health Organization (WHOTrusted Source). Their primary role is to provide energy to all cells in the body. In the absence of carbohydrate intake, the body will use an alternative fuel source called ketones.

The word “carbohydrate” is an umbrella term that describes various types of sugar-containing molecules present in foods.

Types of carbohydrates

Generally, there are three types of carbohydrates: sugars, starches, and dietary fiber.

It is possible to classify them further as simple or complex carbs, depending on the number and type of sugar molecules — such as glucose — that each structure contains.

Simple carbs

Also called “simple sugars,” “sugars,” or “saccharides,” these carbohydrates contain between one and 10 sugar molecules and are present in fruits, vegetables, and dairy products. Those with one or two sugar molecules are called monosaccharides and disaccharides, respectively, while those containing up to 10 sugar molecules are called oligosaccharides.

Lactose — the main sugar in animal milk — is a disaccharide comprising the monosaccharides glucose and galactose.

Oligosaccharides, however, are mid-length prebiotic carbohydratesTrusted Source that are in fiber-rich foods and human milkTrusted Source.

Complex carbs

Complex carbohydrates are made up of polysaccharidesTrusted Source, which are longer, intricate chains of sugar molecules. Complex carbs include both starches and dietary fiber.

Starches are the storage carbohydrates in peas and beans, grains, and vegetables, and they provide the body with energy.

Dietary fiberTrusted Source, or roughage, is the indigestible part of plants — in whole grains, fruits, vegetables, nuts and seeds, and legumes such as peas and beans — that supportsTrusted Source good gut health.

Are there ‘healthy’ and ‘unhealthy’ carbs?

Carbohydrates often get a bad rap due to the associationTrusted Source of their excessive consumption with weight gain, obesity, metabolic syndrome, and diabetesTrusted Source.

This phenomenon, which some researchers call “carbotoxicityTrusted Source,” promotes the idea that the excessive consumption of all types of carbohydrates favors the development of chronic diseases.

For this reason, many low carbohydrateTrusted Source diets have become popular among people interested in losing weight or managing blood sugar levels. They are even in favor among seasoned athletesTrusted Source.

However, several other studiesTrusted Source have demonstrated that the qualityTrusted Source of carbohydrates that people consume is as important as the quantity.

This finding suggests that rather than all carbs being “created equal,” some options are better than others for health.

‘Unhealthy’ carbs

Carbohydrates that people may consider unhealthy because they are less nutritious include:

• refined carbohydrates, such as polished rice and flour
• sugar-sweetened beverages, such as sodas and juices
• highly processed snacks, including cookies and pastries

According to existing research, a diet with a higher intake of these types of carbohydrates and fewer of the more nutritious options can increase markers of inflammationTrusted Source and perpetuate hormonal imbalancesTrusted Source in people with polycystic ovary syndrome (PCOS).

The excessive consumption of simple added sugarsTrusted Source is also linked with an increased risk of insulin resistance, non-alcohol-related fatty liver disease, heart disease, stroke, diabetes, and cancer.

However, studies distinguish that added sugars and simple sugars that occur naturally in foods may not have the same negative effects.

A 2018 studyTrusted Source even suggests that natural sourcesTrusted Source of sugar, such as honey, may be effective in reducing blood sugar levels and lowering the risk of developing type 2 diabetes.

Emerging research continues to shine a light on the adverse health effects of these so-called unhealthy carbohydrate foods.

Experts recommend eating a balanced diet that consists primarily of nutritious foods and includes these types of carbohydrates only in moderation.

‘Healthy’ carbs

More nutrient-dense sources of carbohydrates that people typically see as healthy include:

• fruits, such as bananas, apples, and berries
• nonstarchy vegetables, such as spinach, carrots, and tomatoes
• whole grains, such as whole grain flour, brown rice, and quinoa
• peas and beans, such as black beans, lentil peas, or garbanzo beans
• dairy and dairy products, such as low fat milk, and yogurt

Research has linked diets rich in these complex carbohydrates — such as the Mediterranean dietTrusted Source — with anti-inflammatory benefits, lowered insulin resistance, and a reduced risk of chronic diseases.

The researchers attribute many of these benefits to the dietary fiber content of complex carbohydrates.

For instance, the dietary fiber in whole fruits improvesTrusted Source long-term weight management and supports regular bowel movements and healthy aging.

Furthermore, boosting the quality of the diet by including more complex carbs and dietary fiber can lead toTrusted Source improvements in some of the effects of PCOS, such as insulin resistance and elevated androgens.

A 2020 reviewTrusted Source found that the dietary fiber in whole grain foods confers several health benefits, including a reduced risk of heart diseaseTrusted Source, gut disorders, cancer, and diabetes.

Deciding which carbs are the ‘healthiest’

The glycemic index (GI)Trusted Source and glycemic load (GL)Trusted Source are two measures that people have used to establish the quality of carbohydrate foods and categorize them as “healthy” or “unhealthy.”

The GI is a measure of the blood sugar-raising potential of a single carbohydrate food compared with pure glucose.

Low GI foods, which primarily consist of complex carbs, have minimal effects on blood sugar levels. They include whole grains and nonstarchy vegetables. High GI foods include potatoes and foods with added sugars.

Likewise, people use the GL to assess how much a particular meal is likely to increase blood sugar levels.

Although people have used both the GI and GL for decades to guide meal planning and manage blood sugar levels for people with diabetes, the science is inconclusiveTrusted Source.

Many studies suggest that an increased intakeTrusted Source of low GI foods improves health outcomes, but other studies demonstrate that differencesTrusted Source in daily glucose tolerance and individual responses are responsible for blood sugar levels rather than the GI of the foods themselves.

A food’s GI may, therefore, not be a direct predictor of an individual’s glycemic response.

Differences in glycemic response between individuals make it challenging to determine which carbs are truly the healthiest, since even whole grains may not beTrusted Source a consistent and reliable measure of GI and GL.

Are diets rich in carbs good for you?

Despite the popularity of low carbohydrate dietsTrusted Source, they are not suitable for everyone, and some populations still benefit from a carbohydrate-rich diet.

For example, endurance athletic performance becomes compromisedTrusted Source on a low carbohydrate diet, and a high carbohydrate intake remains the most evidence-backedTrusted Source choice for elite athletes.

Among members of the general population with high carbohydrate intake, significant reductionsTrusted Source in blood sugar levels — potentially promoting the remission of prediabetes — occur when the daily intake of carbohydrates is reduced.

Therefore, for populations that consume 65–75% of their daily calories from carbohydrates, experts recommendTrusted Source reducing carbohydrate calories to 50–55% of daily intake and increasing protein.

A carbohydrate restriction of 45% or less of daily calories is more effectiveTrusted Source for short-term blood sugar control, but it may be unsustainable and does not provide greater long-term results than a range of 50–55% of daily calories from carbohydrates.

Before making changes to their diet, people should speak with a doctor or registered dietitian to determine their specific carbohydrate needs to optimize their health outcomes.

The bottom line

Carbohydrates are an essential macronutrient, providing the body with energy and dietary fiber to support good health.

Excessive consumption of carbohydrates is associated with weight gain and an increased risk of the development of chronic diseases, such as heart disease and diabetes.

Despite their bad rap, however, carbohydrates offer many health benefits when a person frequently consumes sources of complex carbs and dietary fiber in favor of refined carbs and sugar-sweetened beverages.

Also, the ideal diet varies among individuals. For example, a carbohydrate-rich diet optimizes athletic performance.

However, nonathletic populations that consume 65–75% of their daily calories from carbohydrates see the greatest reduction in blood sugar levels when they reduce their calorie intake from carbohydrates to 50–55% of their daily energy intake.

Carbohydrates are not bad when people manage the amount and types that they consume and tailor these to their specific needs.

Source - Medical News Today

Longevity diet: More carbs, fasting, and less protein

Researchers analyzed hundreds of studies to identify a diet that optimizes human health and longevity.

• They found that diets low in animal protein and high in complex carbohydrates that include periods of fasting are most beneficial for long-term health and life span.
• However, the researchers note that their findings simply provide a foundation for understanding and that, in practice, diets should be tailored to individual needs and circumstances.

In around 440 B.C., the Greek physician Hippocrates said “Let food be thy medicine and let thy medicine be food.”

Although treating food as medicine is a highly debated concept, many recent studies have demonstrated the wisdom in this statement and how monitoring food quantityTrusted Source, type, and timing are crucial for good health.

However, what precisely makes up the optimal diet remains controversial. Growing evidence suggests optimal diets may depend on an interplay of health factors, including age, sex, and genetics.

Recently, researchers reviewed hundreds of nutrition studies from cellular to epidemiological perspectives to identify a “common denominator nutrition pattern” for healthy longevity.

They found that diets including mid-to-high levels of unrefined carbohydrates, a low but sufficient plant-based protein intake, and regular fish consumption were linked to an extended lifespan and healthspan.

Dr. Valter Longo, professor of gerontology and biological sciences at the University of Southern California, and one of the authors of the study, told Medical News Today:

“First, diet here is intended as a nutritional lifestyle and not as a ‘weight-loss strategy’ although maintaining a healthy weight is key. All aspects of the diet are linked to long-term health and longevity.”

“I am delighted to see this review,” Dr. Pankaj Kapah, professor of gerontology at the University of Southern California, who was not involved in the study, told MNT.

“Generally when one thinks of a longevity diet, the first thing that comes to mind is what we can add to our diet to live longer. This article is important to raise the awareness that the most striking benefits from studies across species have come from limiting the diet or fasting.”
— Dr. Pankaj Kapah 

 

The foundation of the longevity diet

For the study, the researchers analyzed hundreds of studies examining nutrition and delayed aging in short-lived species, nutrient response pathways, caloric restriction, fasting, and diets with various macronutrient and composition levels, such as the keto diet.

The studies analyzed nutrition and diet from multiple angles, from cellular and animal studies to clinical and epidemiological research investigating the lifestyles of centenarians.

In the end, the researchers found that the ‘longevity diet’ includes:

• A legume and whole grain-rich pescatarian or vegetarian diet
• 30% of calories from vegetable fats such as nuts and olive oil
• A low but sufficient protein diet until age 65 and then moderate protein intake
• Low sugar and refined carbs
• No red or processed meat
• Limited white meat
• 12 hours of eating and 12 of fasting per day
• Around three cycles of a five-day fasting-mimicking diet per year

The researchers further noted that, rather than targeting a certain number of calories, diets should aim to keep BMI under 25 and maintain ideal sex and age-specific body fat and lean body mass levels.

Moreover, they wrote that diets should be adapted to individual needs—especially for those over 65—to avoid malnourishment. Those over 65, for example, may become frail from a low protein diet.

For those without insulin resistance or obesity, high consumption of complex carbohydrates could reduce frailty in this age group and others, the researchers wrote, as it provides energy without increasing insulin and activating glucose signaling pathways.

The researchers also found that periodic fasting between the ages of 18 and 70 could reverse insulin resistance generated by a high calorie diet and regulate blood pressure, total cholesterol, and inflammation.

A recent study supports these findings. It found that changing from the typical Western diet to one rich in legumes, whole grains, and nuts with reduced red and processed meats is linked to an 8-year-longer life expectancy if started at age 60.

 Underlying mechanisms

The researchers noted that diets involving calorie and protein restriction were consistently beneficial, whether in short-lived species or om epidemiological studies and large clinical trials.

They further noted that low but sufficient protein, or a recommended protein intake with high levels of legume consumption, could increase the health span by reducing the intake of amino acids including methionine. Methionine has been linked to increased activity in various pro-aging cellular pathways.

When asked how the longevity diet may benefit health from a clinical perspective, Kristin Kirkpatrick, a registered dietitian nutritionist at the Cleveland Clinic and advisor to Dr. Longo’s firm, Prolon, told MNT:

“The diet is primarily plant-based which, based on other similar studies, may contribute to lower risk of chronic conditions such as type 2 diabetes and cardiovascular disease.”

“Plant-based diets have also been associated with lower inflammation levels in multiple studies. As inflammation is the base of many diseases, this may contribute to the longevity factors as well,” she explained.

The researchers conclude that their findings provide solid foundations for future research into nutritional recommendations for healthy longevity.

When asked about the study’s limitations, Dr. Longo, Dr. Kapahi, and Kirkpatrick stressed that there is no ‘one-size-fits-all’ approach. The optimal diet, they say, may differ due to factors including sex, age, genetic makeup, and any sensitivities and intolerances, such as an intolerance to gluten.

Dr. Longo thus recommends people visit a dietician before undertaking a new diet.

Kirkpatrick added that many of her patients visit her when making dietary changes to ensure they are sustainable in the long term.

FROM OUR EXPERT NUTRITIONISTS

29 nutrition tips for better health and longevity 

Good nutrition is a critical part of health and development. According to the World Health Organization (WHO), better nutrition is related to improved health at all ages, a lower risk of diseases, and longevity.

 People can find it difficult or confusing to navigate the amount of nutrition information now available, and many sources have differing views.

This article offers science-based nutrition tips to help someone lead a healthier lifestyle.

Nutrition tips for diet

Following these nutrition tips will help a person make healthy food choices.

1. Include protein with every meal

Including some protein with every meal can help balance blood sugar.

Some studiesTrusted Source suggest higher protein diets can be beneficial for type 2 diabetes.

Other researchTrusted Source indicates balancing blood sugar can support weight management and cardiovascular health.

2. Eat oily fish

According to researchTrusted Source, omega-3 fatty acids in oily fish are essential for cell signaling, gene expression, and brain and eye development.

Some studiesTrusted Source indicate that omega-3 fatty acids can reduce the risk of cardiovascular disease.

Other researchTrusted Source suggests the anti-inflammatory properties of omega-3 may effectively manage the early stages of degenerative diseases such as Alzheimer’s disease and Parkinson’s disease.

3. Eat whole grains

The American Heart Association (AHA)Trusted Source recommend people eat whole grains rather than refined grains.

Whole grains contain nutrients such as B vitamins, iron, and fiber. These nutrients are essential for body functions that include carrying oxygen in the blood, regulating the immune system, and balancing blood sugar.

4. Eat a rainbow

The saying ‘eat a rainbow’ helps remind people to eat different colored fruits and vegetables.

Varying the color of plant foods means that someone gets a wide variety of antioxidants beneficialTrusted Source to health, for example, carotenoids and anthocyanins.

5. Eat your greens

Dark green leafy vegetables are a great source of nutrition, according to the Department of Agriculture (USDA).

Leafy greens are rich in vitamins, minerals, and antioxidants.

The USDA suggest that folate in leafy greens may help protect against cancer, while vitamin K helps prevent osteoporosis.

6. Include healthful fats

People should limit their intake of saturated fats while avoiding trans fats, according to the USDA.

A person can replace these fats with unsaturated fats, which they can find in foods such as avocado, oily fish, and vegetable oils.

7. Use extra virgin olive oil

As part of the Mediterranean diet, extra virgin olive oil has benefits to the heart, blood pressure, and weight, according to a 2018 health reportTrusted Source.

A person can include extra virgin olive oil in their diet by adding it to salads or vegetables or cooking food at low temperatures.

8. Eat nuts

According to the AHATrusted Source, eating one serving of nuts daily in place of red or processed meat, french fries, or dessert may benefit health and prevent long-term weight gain.

The AHA suggest that Brazil nuts, in particular, may help someone feel fuller and stabilize their blood sugar.

9. Get enough fiber

According to the AHATrusted Source, fiber can help improve blood cholesterol levels and lower the risk of heart disease, obesity, and type 2 diabetes.

People can get enough fiber in their diet by eating whole grains, vegetables, beans, and pulses.

10. Increase plant foods

ResearchTrusted Source suggests that plant-based diets may help prevent overweight and obesity. Doctors associate obesity with many diseases.

According to some studies, including more plant foods in the diet could reduceTrusted Source the risk of developing diseases such as diabetes and cardiovascular disease.

11. Try beans and pulses

Beans and pulses are a good source of protein for people on a plant-based diet. However, those who eat meat can eat them on a few meat-free days a week.

Beans and pulses also contain beneficial fiber, vitamins, and minerals.

Some researchTrusted Source even says pulses may help people feel fuller and lose weight.

 Nutrition tips for what to drink

Drinking plenty of healthy fluids has numerous health benefits. Health experts recommend these tips:

12. Drink water

Drinking enough water every day is good for overall health and can help manage body weight, according to the Centers for Disease Control and Prevention (CDC)Trusted Source.

Drinking water can prevent dehydration, which can be a particular risk for older adultsTrusted Source.

If someone does not like plain water, they can add some citrus slices and mint leaves to increase the appeal, or drink herbal teas.

13. Enjoy coffee

A 2017 study suggests that moderate coffee consumption of 3–5 cups a day can reduce the risk of:

• type 2 diabetes
• Alzheimer’s disease
• Parkinson’s disease
• cardiovascular diseases

According to the same review, the recommended amount reduces to 2 cups per day for pregnant and lactating people.

14. Drink herbal teas

According to researchTrusted Source, catechins in green, black, and other herbal teas may have antimicrobial properties.

Herbal teas, such as mint, chamomile, and rooibos, are caffeine-free and help keep someone hydrated throughout the day.

Nutrition tips for foods and drinks to avoid

It is important to cut back on food and drink that may have harmful health consequences. For example, a person may want to:

15. Reduce sugar

According to researchTrusted Source, dietary sugar, dextrose, and high fructose corn syrup may increase the risk of cardiovascular disease and metabolic syndrome.

People should look out for hidden sugars in foods that manufacturers label as names ending in “-ose,” for example, fructose, sucrose, and glucose.

Natural sugars, such as honey and maple syrup, could also contribute to weight gain if someone eats them too often.

16. Drink alcohol in moderation

Dietary Guidelines For AmericansTrusted Source recommend that if someone consumes alcohol, it should be in moderation.

They advise up to one drink per day for females and up to two drinks per day for males.

Excessive drinking increases the risk of chronic diseases and violence, and over time, can impair short and long-term cognitive function.

17. Avoid sugary drinks

The CDCTrusted Source associate frequently drinking sugary drinks with:

• weight gain and obesity
• type 2 diabetes
• heart disease
• kidney disease
• non-alcoholic liver disease
• tooth decay and cavities
• gout, a type of arthritis

People should limit their consumption of sugary drinks and preferably drink water instead.

18. Eat less red and processed meat

A large prospective study in the British Medical JournalTrusted Source indicates that U.S. adults eating more red and processed meat had higher mortality rates.

Participants who swapped meat for other protein sources, such as fish, nuts, and eggs, had a lower risk of death in the eight-year study period.

19. Avoid processed foods

According to a review in Nutrients, eating ultra-processed foods can increase the risk of many diseases, including cancer, irritable bowel syndrome, and depression.

People should instead consume whole foods and avoid foods with long lists of processed ingredients.

Other good health habits

There are several steps a person can take to improve their health in addition to consuming healthful foods and drinks.

20. Support your microbiome

A 2019 review in NutrientsTrusted Source suggests that a high quality, balanced diet supports microbial diversity and can influence the risk of chronic diseases.

The authors indicate that including vegetables and fiber are beneficial to the microbiome. Conversely, eating too many refined carbohydrates and sugars is detrimental.

21. Consider a vitamin D supplement

The recommended dietary allowance for vitamin D is 15 micrograms or 600 international unitsTrusted Source per day for adults.

Many people get some of their vitamin D from sunlight, while it is also in some foods.

People with darker skin, older adults, and those who get less exposure to sunlight — such as during winter or in less sunny climates — may need to take a vitamin D supplement.

22. Be aware of portion size

Being aware of portion sizes can help people manage their weight and diet.

The USDATrusted Source have helpful information about portion sizes for different food patterns.

People can adapt the guidelines to suit their cultural or personal preferences.

23. Use herbs and spices

Using herbs and spices in cooking can liven up a meal and have additional health benefits.

A 2019 reviewTrusted Source suggests that the active compounds in ginger may help prevent oxidative stress and inflammation that occurs as part of aging.

Curcumin in turmeric is anti-inflammatory and may have protective effects on health, according to researchTrusted Source.

Garlic has many benefitsTrusted Source, including anti-inflammatory, antimicrobial, and antioxidant properties.

24. Give your body a rest by fasting

Intermittent fasting involves not eating either overnight or some days of the week. This may reduce energy intake and can have health benefits.

According to a 2020 reviewTrusted Source, intermittent fasting may improve blood pressure, cholesterol levels, and heart health.

25. Keep a food journal

The American Society for Nutrition say that keeping a food journal can help people track calories, see how much they are eating, and recognize food habits.

Keeping a food journal could help someone who wants to maintain a moderate weight or eat a more healthful diet.

Apps, such as MyFitnessPal, can also help someone achieve their goals.

26. Wash fruits and vegetables

Raw fruits and vegetables can contain harmful germs that could make someone sick, according to the CDCTrusted Source. They advise that Salmonella, E.coli, and listeria cause a large percentage of U.S. foodborne illness.

Always wash fresh produce when eating them raw.

27. Do not microwave in plastic containers

ResearchTrusted Source suggests that microwaving food in plastic containers can release phthalates, which can disrupt hormones.

Experts recommend heating food in glass or ceramic containers that are microwave-safe.

28. Eat varied meals

Many people eat the same meals regularly. Varying foods and trying different cuisines can help someone achieve their required nutrient intakeTrusted Source.

This can be particularly helpful when trying to eat a broader range of vegetables or protein.

29. Eat mindfully

In a 2017 studyTrusted Source, mindful eating helped adults with obesity eat fewer sweets and manage their blood glucose.

Another studyTrusted Source suggests mindfulness can bring greater awareness to food triggers and habits in people with diabetes.

Summary

Nutrition is an essential part of health, and people can start leading a healthful lifestyle by making small changes to their diet.

It is also important to remember other key aspects of health, such as exercise and activity, stress strategies, and adequate sleep.

 Source - Medical News Today