You don't eat enough vegetables if this happens to your body

We've been hearing "eat your vegetables" since we were kids, but most Americans still aren't getting enough. According to research conducted by the Centers for Disease Control and Prevention, a measly 9.3 percent of American adults eat the recommended amount of vegetables.

The U.S. Department of Agriculture (USDA) recommends that women between the ages of 19 and 50 eat 2.5 cups of vegetables a day while those 51 and older should aim for 2 cups. Adult men 50 and under should consume 3 cups, while 2.5 cups is sufficient for older men. The USDA breaks down the vegetable food group into five subgroups — dark-green vegetables, starchy vegetables, red and orange vegetables, beans and peas, and other vegetables (like onions and lettuce) — and provides specific weekly recommendations for each subgroup.

The USDA's recommendations can be thought of as a bare minimum for good health. Some people, such as those who are extremely physically active, may need more. There are many subtle — and not so subtle — ways your body may be trying to tell you that it needs more vegetables.

Can't shed the pounds? Try eating more vegetables

If you're trying to lose weight, you're not alone. Data collected from the National Health and Nutrition Examination Survey found that 56.4 percent of women and 41.7 percent of men are actively trying to lose weight (via Time). If the scale won't budge, it may be a sign that you need to incorporate more veggies into your diet.

Losing weight by eating more vegetables isn't magic; it's math. To lose weight you need to expend more calories than you consume, the Centers for Disease Control and Prevention (CDC) explained. Unlike fattening favorites like pizza and ice cream, vegetables are low-calorie, high-volume foods. Their fiber content also slows digestion, keeping you feeling fuller longer. The CDC suggested substituting vegetables for higher-calorie ingredients throughout your day. For example, consider substituting spinach, onions, and mushrooms for an egg or half the cheese in your breakfast omelet. When it comes time for a snack, choose carrot sticks with hummus over a candy bar or chips.

If you're always constipated, you may need to eat more fiber-rich vegetables

"Dietary fiber, also known as roughage or bulk, includes the parts of plant foods your body can't digest or absorb," according to the Mayo Clinic. It comes in two forms: soluble and insoluble. Soluble fiber absorbs water as it passes through your digestive tract whereas insoluble fiber doesn't. Although both types of fiber are beneficial, the insoluble kind is responsible for keeping you regular. It "promotes the movement of material through your digestive system and increases stool bulk." Adult women should aim to get 21 to 25 grams of fiber a day, depending on age, while men should shoot for 30 to 38 grams.

If you aren't getting enough fiber elsewhere in your diet (such as from whole grains) and your trips to the bathroom are less than optimal, add more fiber-rich vegetables to your plate. Beans and other legumes are the best choice. A cup of boiled pinto beans, for example, contains 14.7 grams while a half-cup of green peas offers 4 grams. Other excellent choices include artichokes (6.2 grams per medium vegetable), canned pumpkin (5 grams per half-cup), and skin-on baked potatoes (5 grams per medium spud).

You may need to eat more vegetables if you can't get your cholesterol under control

High cholesterol is a big problem in the United States. The Centers for Disease Control and Prevention reported that 93 million American adults have total cholesterol levels above 200 mg/dL. This puts them at greater risk for heart disease and stroke. Inadequate vegetable intake is also a big problem in the United States, and research suggest that solving that problem could go a long way in combatting the high cholesterol crisis.

A study published in The American Journal of Clinical Nutrition examined more than 4,000 adults to determine if there was a relationship between fruit and vegetable intake and levels of low-density lipoprotein (aka LDL or "bad") cholesterol. They found that the LDL cholesterol of participants who ate more than four servings of fruits and vegetables a day was indeed "associated with lower concentrations of LDL cholesterol." But how do vegetables lower cholesterol?

Medline Plus explained, "A diet rich in fruits and vegetables can increase important cholesterol-lowering compounds in your diet. These compounds, called plant stanols or sterols, work like soluble fiber."

High blood pressure can be a sign you're not getting enough nitrate-rich vegetables

You've heard that nitrates are the ingredient that makes bacon so bad for you, but did you know that there are other nitrates you should be trying to get more of in your diet? Unlike the synthetic nitrates used as preservatives, the natural nitrates found in some fruits and vegetables appear to be beneficial for health. Vegetables high in these nitrates include dark leafy greens, beets, radishes, turnips, and celery.

A study published in the New England Journal of Medicine examined the effect nitrates had on participants' blood pressure. As WebMD said of the findings, "Average diastolic blood pressure (the bottom number in a blood pressure measurement) was 3.7 mm Hg lower after three days of nitrate supplementation." Nitrates appear to help keep blood vessels healthy and adequately dilated, thus reducing blood pressure.

This is good news because hypertension — 130/80 mm Hg or higher — affects approximately 45 percent of American adults. It's considered a major risk factor for both heart disease and stroke.

Eat more vegetables high in vitamin C if you get sick all the time

When you hear the words "vitamin C," the first thing that probably comes to mind is chugging glass after glass of orange juice to combat a cold. While many fruits are rich sources of vitamin C, some vegetables also offer a hefty serving of this important micronutrient. One cup of raw red bell pepper, for instance, provides 211 percent of your daily value (DV) while a cup of raw broccoli has 90.2 percent and a cup of raw Brussels sprouts provides 79.8 percent.

Vitamin C is, as you may have assumed, essential for the immune system. According to a 2017 article published in the journal Nutrients, vitamin C helps give skin its structure, creating a first-line defense against invading germs. It accumulates in phagocytes, a group of white blood cells designed to destroy germs by "eating" them. It's also needed for apoptosis, the destruction and recycling of old or damaged cells.

Additionally, vitamin C aids lymphocytes, another type of immune cell, differentiate into specialized B and T cells, designed to target specific invaders the body has encountered in the past. The article's authors pointed out that vitamin C deficiency "results in impaired immunity and higher susceptibility to infections."

If your skin looks older than it is, up your intake of micronutrient-rich vegetables

In 2017, the New York Post reported on a nationwide survey that found that many women worry about their skin aging gracefully. Results showed that 28 percent of women under 25, 42 percent of women aged 25 to 34, and 54 percent of women between the ages of 35 and 44 worried regularly about wrinkles, sagging, and the other physical signs of aging.

Instead of investing in expensive creams and serums, try upping your vegetable intake to keep your skin looking young from the inside out. A 2012 article published in the journal Dermatoendocrinol reviewed the micronutrients most beneficial to skin health. Spoiler alert: Many of them are found in vegetables. Vitamin C is plentiful in many vegetables (including broccoli, cauliflower, and potatoes) and helps build the collagen that gives skin its firmness.

Also found in some vegetables are beta-carotene and lycopene, powerful antioxidants that protect skin from sun damage. Carrots, pumpkin, and sweet potatoes are excellent sources of beta-carotene whereas red vegetables, such as red bell peppers and tomatoes, contain lycopene.

Bruising easily may be a sign that you need to eat more vegetables

If just lightly bumping into things leaves you black and blue for days, it could be a sign that you're not getting enough vitamins C and K, Cory Fisher, family medicine physician at the Cleveland Clinic told PreventionThankfully, both of these vitamins are plentiful in vegetables.

Vitamin C is necessary for strengthening your skin. "Without enough of it, your blood vessels are out in the open and more likely to rupture," the site revealed. Vitamin K, on the other hand, may not be as well known as other vitamins, but it's just as essential for good health. Your body uses vitamin K to produce proteins that oversee blood clotting, Healthline explained.

This process prevents excessive bleeding both externally and internally. Easy bruising is an early sign of inadequate vitamin K levels. Although our bodies can produce one form of vitamin K, known as K2 (menaquinone), we get most of the vitamin K we need from food in the form of vitamin K1 (phylloquinone). Kale, spinach, collard greens, and other leafy green veggies are the best sources of vitamin K.

Trouble seeing at night? Eat more vegetables

If your eyes have trouble transitioning from a bright environment to a dark one or driving after sunset has become a challenge, you may be experiencing nyctalopia, or night blindness. There are some common causes for this vision impairment, including cataracts and myopia (nearsightedness), but a vitamin A deficiency is occasionally to blame. 

Vitamin A is needed to produce rhodopsin, a protein that allows the eyes to function in low light. Vitamin A is also important for maintaining a clear cornea (the outside covering of the eye) and may reduce your risk for cataracts and, thus, further reduces your risk of night blindness. Sweet potatoes, leafy green vegetables, pumpkin, bell peppers, and carrots are excellent sources of this vitamin.

Lutein and zeaxanthin are two other substances crucial to vision. As an article published in Nutrition Reviews explained, these carotenoids (plant pigments) are taken up by the eye, where they "may be protective against eye disease because they absorb damaging blue light that enters the eye." In addition to safeguarding the eyes from diseases such as macular degeneration, lutein and zeaxanthin also appear to play a role in visual development and proper functioning of the retina. The best sources of these carotenoids are kale, spinach, parsley, green peas, lettuce, and squash.

You probably need to eat more vegetables if even small wounds take forever to heal

Nature's Band-Aid might just be a bell pepper. According to a 2015 review published in the journal Wounds, many micronutrients found in vegetables play an important role in healing cuts and scrapes. Vitamin A, for one, stimulates growth of epithelial cells, which make up the epidermis or outermost layer of skin. Vitamin A also has an anti-inflammatory effect on wounds.

Vitamin C also plays an important role in all phases of wound healing, a 2013 paper published in the British Journal of Community Nursing outlined. During the initial inflammatory phase, vitamin C is required to clear away cells after they've performed their function, preventing inflammation from getting out of control. In the proliferative phase, when new tissue is being created, vitamin C is needed for collagen production, which strengthens the skin. During the maturation phase of healing, when collagen is realigned into an orderly network of fibers and the wound fully closes, insufficient vitamin C can actually lead to scarring.

Bell peppers are an especially great vegetable to consume because they contain both vitamins C and K. If you're not a fan of peppers, that's okay; Brussels sprouts and broccoli also contain both of these protective vitamins.

Eat more potassium-rich vegetables to avoid painful muscle cramps

That National Institutes of Health recommends that adult men get 3,400 mg of potassium daily while women should aim for 2,600 mg. But, according to Oregon State University, no one in the United States is hitting that mark. None of the people they surveyed met the estimated average requirement for potassium, with average intake among both men and women at 2,595 mg. The researchers noted that "fruit and vegetables were the main dietary source of the mineral, comprising 20% of total potassium intake, about half of which came from white potatoes."

Low potassium levels can lead to sudden, painful muscle cramps. As Healthline explained, potassium helps relay signals from the brain to the muscles, causing them to contract. When potassium leaves muscle cells, this causes the muscle contractions to end. "When blood potassium levels are low, your brain cannot relay these signals as effectively. This results in more prolonged contractions, such as muscle cramps," the site explained.

Although bananas are the poster child for potassium, many vegetables actually offer more per serving. These include sweet potatoes, white potatoes, beets, spinach, Swiss chard, and butternut squash.

If you're always tired, try eating more vegetables

Your energy drink or morning coffee may promise to get you through the midday slump, but calories (from carbs, fat, and protein) are the only thing that actually provides our bodies with real energy. Micronutrients, however, play a supporting role, helping our bodies extract, use, and regulate the energy calories provide.

A 2020 article published in the journal Nutrients outlined how various vitamins and minerals influence our energy levels. The authors explained, "All the B vitamins except folate are involved in at least one and often in several steps of the energy-production system within the cell." These include thiamine (B1), riboflavin (B2), niacin (B3), and pyridoxine (B6), among others. Good vegetable sources of B vitamins include romaine lettuce, spinach, and sweet potatoes.

The article also highlighted the importance of vitamin C (found in abundance in vegetables like bell peppers, broccoli, and Brussels sprouts) and magnesium for energy production. Dark leafy greens are a good source of magnesium, as well as vitamin C.

If you always feel down, you may not be getting enough vegetables

Major depression affects an estimated 17.3 million American adults, making it one of the most common mental disorders in the U.S., according to the National Institutes of Health. While depression is a complex condition with many biological and psychological factors, diet may play an important role. In fact, Harvard Medical School noted, "Diet is such an important component of mental health that it has inspired an entire field of medicine called nutritional psychiatry."

A 2015 meta-analysis published in Nutrition examined eight previously published studies that explored the connection between vegetable consumption and depression (as well as 10 studies focused on fruit intake). The researchers concluded that vegetable intake was inversely associated with depression. But what exactly do veggies contain that makes them so good for our mental health?

The answer, according to Medical News Today, is likely antioxidants like vitamins A and C, which protect the brain from free radicals, and the B vitamin folate, which helps maintain the nervous system. Positive dietary changes, however, are no substitute for medication or psychotherapy. If you're struggling with depression, there are many resources that can help.

Having trouble remembering things? Try upping your intake of folate-rich vegetables

The National Institutes of Health (NIH) recommends that adult men and non-pregnant women get 400 mcg of folate daily, while pregnant women need 600 mcg and breastfeeding mothers require 500 mcg.

In addition to assisting with the synthesis of DNA and RNA, folate is necessary for the conversion of the amino acid homocysteine to methionine, another amino acid more useful in the body. This is important for brain health because, according to the NIH, many studies have shown that higher homocysteine levels are associated with both Alzheimer's disease and dementia. NIH further revealed, "Some, but not all, observational studies have also found correlations between low serum folate concentrations and both poor cognitive function and higher risk of dementia and Alzheimer's disease."

A study published in The Lancet followed over 800 Dutch participants for three years to see how folate supplementation affected their cognitive abilities. They found that those receiving the folate scored higher on tests of memory, information processing speed, and sensorimotor speed than those receiving the placebo. To get more folate, look to vegetables like spinach, asparagus, Brussels sprouts, lettuce, broccoli, and mustard greens.

If you're having trouble getting pregnant, consider eating more vegetables

Although it's a topic often shrouded in shame, infertility is actually very common. According to the National Institutes of Health, approximately 11 percent of women and 9 percent of men struggle with infertility, which is defined as the inability to conceive after a year of trying. While infertility can have many causes outside of one's control, eating a diet rich in certain micronutrients may just increase the chances of getting pregnant.

Folate (vitamin B9) is one of the most important vitamins for reproductive health. It's included in prenatal vitamins because folate deficiency can lead to neural tube defects in the developing fetus. A study published in Obstetrics & Gynecology in 2015 concluded that folate may also help women find greater success with assisted reproductive technology. The authors noted that "higher folate intake was associated with higher rates of implantation, clinical pregnancy, and live birth."

Women who consumed the most folate were 20 percent more likely to have a successful pregnancy than women who consumed the least folate. Vegetables are a rich source of folate; the best choices include spinach, Brussels sprouts, asparagus, and romaine.