A Natural Weight Loss Food: Consuming Corn to Shed Extra Pounds
Whether you eat it right off the cob or from a can, as a side dish or a movie-night popcorn, or have it grilled to savory and served up with a light smear of butter and a dash of salt, corn deserves a part in your diet as a nutritious and healthy snack (1)(2).
With all the rumors surrounding how corn is grown to its nutrient content, people have raised questions regarding the health benefits of corn (1). Contrary to popular belief, corn does deserve a regular spot in your diet. Its low-fat profile includes healthy fiber, antioxidants, vitamins and minerals. Moreover, corn also offers tons of benefits for your eyes, bones, and digestive system (2).
What is Corn?
Corn, also known as makai, bhutta, or maize, is known as one of the most important crops in the world. It has tons of nutritional benefits and uses in the food industry (4). For one, we consume corn in various ways, from corn on the cob to cereals, tortillas, and popcorn. More so, we also make use of its by-products, such as corn oil and high-fructose corn syrup, which are universal in a lot of packaged foods (5).
This low-fat complex carbohydrate (6) is a staple food – one of the most commonly eaten and grown foods in the world (7). It comes as kernels on a cob, covered by a husk. As a starchy vegetable, corn often has its benefits overlooked due to its natural sugar and carbs – which can spike blood sugar levels – and the fact that it is genetically modified (3). Still, being both a vegetable and grain makes corn an incredibly healthy and versatile food (2)(8).
Corn is a cereal grain that originated in southern Mexico (5). Ten-thousand years ago, farmers in southern Mexico first cultivated corn from a wild grass known as teosinte. Compared to modern corn kernels, teosinte kernels were much smaller. As the farmers carefully picked which corn seed they would replant, corn evolved into the version we know today (8).
From there, its popularity also grew across the globe. Natives in North and South America grew corn, which they call maize. Europeans who came to New England learned about it and applied it back to their home countries. The members of the Wampanoag and pilgrims of Plymouth Colony were likely to include corn at the first Thanksgiving dinner in 1621 (8).
Types of Corn
Corn is both a cereal grain and a vegetable. Today, it is the most widely consumed cereal grain worldwide (3).
Corn is usually white or yellow, but it can also come in colors like red, purple, and blue. It can also be eaten as sweet corn, polenta, tortillas, popcorn, cornmeal, chips, syrup, oil, and grit, to say the least. Moreover, forty percent of the corn grown in the US is used as fuel, and sixty to seventy percent of corn worldwide is used for animal feed (3).
Either as a vegetable or grain, corn comes in different types:
1. Sweet Corn
There are over 200 varieties of corn grown in the United States alone, where sweet corn is a popular tradition among several families (7). As per the Dietary Guidelines for Americans, sweetcorn – or corn on the cob – is a traditional summertime favorite considered to be a member of the starchy vegetable group. Depending on maturation, color, and sweetness, there are different variations of sweet corn that exist. This type of corn is also available canned or frozen – with varieties that include bicolor, white, and creamed (2).
Sweet corn is high in carbs, fiber, vitamins and minerals. This genetic variant of corn contains more sugar and less starch (5). As per Rinki Kumari, Chief Dietician in Fortis Hospital, Cunningham Road, Bangalore, sweetcorn is a good probiotic as it contains a certain kind of good gut bacteria, which aids in digestion and better metabolism, eventually leading to weight loss (4).
Kumari adds that sweet corn also helps to maintain healthy skin, vision, and mucosa – a membrane that lines various cavities in the body and covers the surfaces of internal organs – as it contains antioxidants and vitamins A, B, and C (4).
She also explains that sweet corn contains healthy amounts of essential minerals like magnesium, zinc, copper, manganese, and iron. It is also a gluten-free cereal used for celiac disease. In addition to its weight loss benefits, it offers the necessary calories for daily metabolism (4).
Kumari warns that one must consume sweet corn in moderation to rep its benefits (4).
2. Baby Corn
Whole baby corn is a miniature sweet corn that is harvested at a very young age when the kernels are still at the incipient age. Compared to other types of corn, baby corn is sweet and tender enough to be eaten raw (2). But, as it matures, the corn cob – the part which the kernels grow – becomes harder and inedible (5).
3. Flint or Indian Corn
Flint or Indian corn is harder than sweet corn. It comes in various colors, which includes white, red, blue, gold, and black. This type of corn grows in Central and South America. In the United States, this corn is usually used for fall decorations (8).
Corn is considered as a grain when it is left to dry (2). There are different types of grains when it comes to this variant of corn:
The dry seeds used for popcorn are classified as whole grains (3). Note, however, that not all corn will pop. Popcorn is a specially cultivated variant. It is made up of a hard, moisture-resistant hull that surrounds a dense pocket of starch, which explodes when heat from steam builds up inside the hull (2).
Initially, popcorn has a soft, starchy center that is surrounded by a hard gold-colored shell. Inside of each is a tiny droplet of water. When you heat popcorn in the pan or microwave, the moisture inside gives off steam. Pressure from steam builds to the point where the kernel explodes, and the center opens into a fluffy white nugget (8).
It is known that the nutritional content of corn is best preserved when eaten either whole or as popcorn. Traditionally, Indian preparations use the entire grain, such as in “makkai ki roti” (made from cornmeal, popcorn, bhuna bhutta, and most sweetcorn preparations (4).
Dent corn, or field corn, is another grain used to livestock feed, manufactured gods, and ethanol production (2)(9). Other than that, a small portion of this corn is processed as products for human consumption, such as corn cereal, corn starch, corn oil, and corn syrup (9).
Ninety-nine percent of corn grown in Iowa is dent corn. From the name itself, dent corn has a dent at the top of each kernel. This type of corn comes in either white and yellow. It is mainly used as animal feed and manufactured foods, such as grits and tortilla chips (8). Dent corn is the classic big ears of yellow dented corn that you often see dried and harvested in the fall (9).
As per the United States Department of Agriculture (USDA), a cup (or 166-gram) serving size of corn grain or yellow corn contains:
- Water: 17.21 g (5)
- Energy: 605.90 kcal/ 2534.82 kJ (5)
- Protein: 15.64 g (5)
- Fats: 7.87 g (5)
- Ash: 1.99 g (5)
- Carbohydrates: 123.27 (5)
- Dietary Fiber: 12.12 g (5)
- Sugar (including NLEA): 1.06 g (5)
- Calcium: 11.62 mg (5)
- Iron: 4.50 mg (5)
- Magnesium: 210.82 mg (5)
- Potassium: 476.42 mg (5)
- Sodium: 58.10 mg (5)
- Zinc: 3.67 mg (5)
- Carotene, beta: 161.02 µg (5)
- Carotene, alpha: 104.58 µg (5)
- Vitamin A, IU: 355.24 IU (5)
- Vitamin A, RAE: 18.26 µg (5)
- Vitamin B-6: 1.03 mg (5)
- Vitamin E (alpha-tocopherol): 0.81 mg (5)
- Vitamin K (phylloquinone): 0.50 µg (5)
Other than the above-mentioned nutritional content, corn is also a good source of several other vitamins like folic acid, niacin, and vitamin C (6). Vitamin C is an antioxidant that helps protect your cells from damage and prevent diseases like cancer and heart disease (8).
The folic acid in corn is important for preventing neural-tube birth defects. It’s important in preventing heart disease. According to studies, folic acid can prevent buildup of an amino acid, known as homocysteine, in the body. It is known that long-term elevation of homocysteine is related to higher rates of heart disease, and folic acid contributes to breaking it down (6).
Corn is also a great source of carotenoids lutein and zeaxanthin, which are great for eye health. These help prevent the lens from damage, which leads to cataracts (8). Not only is carotene responsible for the yellow coloration of corn, but it also helps prevent oxidative reactions and cancers (4).
It also has smaller amounts of vitamins B, E, and K, along with minerals like potassium and magnesium, yet is rich in carbohydrates (4)(8). According to the USDA National Nutrient Database, corn also provides the necessary calories for healthy daily metabolism along with these vitamins and minerals (5).
In addition, ferulic acid is a unique phytochemical mostly found in grains, fruits, and vegetables in very low amounts. Surprisingly, it is found in high quantities in corn. Cooking corn further increases the amount of ferulic acid significantly (4).
It is also a great source of potassium – an essential nutrient that a lot of Americans don’t get enough of. Potassium aids in the regulation of the circulatory system, maintaining adequate blood flow and a strong heartbeat. Very low potassium levels eventually lead to a serious condition known as hypokalemia (7).
Health and Weight Loss Benefits
Thanks to its numerous quality nutrients, corn offers tons of health and weight loss benefits. Some of the most recognized benefits include:
Aids in Digestive Health
Corn is high in fiber. As a matter of fact, it is extremely difficult to digest (6). The fiber in sweetcorn adds to the bulk that helps move food through your stomach, intestines, then out of your body. Eventually, this potentially prevents diarrhea and constipation, while decreasing your risk for developing hemorrhoids or diverticular disease, as mentioned by Mayo Clinic (2).
An 18-year study in more than 47,000 adult men associated eating popcorn at least twice a week with a significantly lower risk of diverticular disease. Based on these limited results, eating popcorn and corn helps to promote gut health and prevent digestive diseases. Still, more research is needed (3).
This insoluble fiber also tackles common digestive ailments like hemorrhoids and constipation by absorbing water, which swells the stool and speeds its movement (6). Dietary fiber intake has also been linked to several diseases, which includes heart disease and certain cancers. Furthermore, it promotes healthy digestion and may even protect you against gut issues (3).
Fiber is essential to keep your digestive system in tip-top shape and keep you regular. Both popcorn and sweetcorn offer 10 percent of the recommended daily value with 2.4 grams per serving (2).
As per the American Heart Association, fiber can help improve your blood cholesterol levels, reduce your risk for heart disease and stroke, while also managing Type 2 diabetes. According to Dietary Guidelines, your daily diet should include between 22.4 and 33.6 gram of fiber, depending on your gender and age (2).
Yellow corn is a rich source of beta-carotene, which is responsible for the formation of vitamin A in the body and for good skin and vision maintenance. A study published in the journal Science showed that beta-carotene is a great source of vitamin A, as it is converted into the body according to the amount required (5).
Note, however, that vitamin A can be toxic if consumed excessively, so deriving it through beta-carotene transformation is the best way to achieve the desired amount. This may also benefit your skin health and mucous membranes, and improves your immune system (5).
On one hand, the amount of beta-carotene in the body that is not converted into vitamin A serves as a very strong antioxidant, as all carotenoids are, and combats diseases (5)
Yellow corn is also an excellent source of carotenoids zeaxanthin and lutein (8). Lutein is a carotenoid that is similar to vitamin A, yet is more commonly found in fruits and vegetables. It is known for lowering the risk of macular degeneration, cataracts, and other eye conditions (7).
Zeaxanthin and its isomer lutein are fat-soluble antioxidant carotenoids found in the retina of your eye. They contribute to the characteristic color of yellow corn. Unfortunately, your body can’t synthesize these compounds, so they must be supplied by your diet (2).
These two carotenoids are likely to prevent cataracts and age-related macular degeneration (AMD). This is due to the fact that lutein and zeaxanthin make up a large part of your eye’s macular region (3).
A study of 365 adults found that those with the highest intake of carotenoids – especially lutein and zeaxanthin – are 43 percent less likely to develop AMD compared to those with the lowest intake (3).
In a 2017 study published in Nutrients, corn was used as one of the food sources to evaluate the association between lutein and zeaxanthin and eye health. The results showed that a diet that contains lutein and zeaxanthin can possibly prevent or delay the progression of macular degeneration – the leading cause of blindness (2).
In conclusion, regularly eating corn can promote eye health – especially people who are at risk of AMD (3).
Aids in Weight Loss
One plain ear of corn contains about 100 calories, which is similar to an apple. With nearly 3 grams of fiber per serving, corn can also help you feel full longer – leading you less likely to overeat and gain more pounds (1).
The high dietary fiber content in corn helps you manage weight by slowing in digestion and making you feel full sooner. This would then prevent you from snacking, allowing you to get fewer calories overall. For effective weight loss, Harvard Health Publishing suggests eating 30 grams of fiber everyday (2).
Corn also contains resistant starch – a slow-to-digest type of carb that has been proven to help with weight control (1). When taken in excessive amounts, however, it may contribute to weight gain and spike your blood sugar (3).
A 24-year Harvard study in 133,468 adults found that, for every additional daily serving of corn was associated with 2-pound (0.9-kg) weight gain every 4 years. Starchy vegetables like potatoes and peas were not able to contribute the same amount for weight gain (3).
The glycemic index (GI) of corn is fairly high; therefore, weight conscious people and diabetic people should consume corn in moderation (4). The GI is a ranking of how fast a carbohydrate food raises your blood glucose level. The carbs in corn measure between 55 and 60 on the GI, and it is known that a rating of 55 or less is considered a low value (2).
You may also think that eating high-carb foods like corn or popcorn makes you gain weight. However, a 2018 analysis found in Nutrients shows that a high-carb diet, in combination with low fats, high fiber and foods on the GI, gives off a positive effect on weight management (2).
The results of the study showed that, after 16 weeks, overweight participants experienced overall loss of body fat and weight as well as a decrease in insulin resistance without any exercise (2).
Preparation and Storage
In a 2017 study published in Nutrition, researchers found that cooking foods that contain carotenoids – like corn – improves their bioavailability compared to uncooked foods (2).
Traditionally, Indian preparation makes use of the entire grain, such as in ‘makkai ki roti’ made from cornmeal, bhuna bhutta, popcorn, and most sweetcorn preparations (4).
Boiling is the traditional method for preparing sweet corn, although steaming, grilling, and even microwaving will also get the job done right. When boiling, take note that (6):
- Adding salt to the water will toughen the corn (6).
- Adding sugar is not necessary (6).
- Overcooking toughens kernels (6).
- Cook corn for the shortest amount of time possible – like five minutes (6).
Although butter or margarine seems like a good idea to make this food even more delicious, keep in mind that each pat you add contributes around 2 unnecessary grams of saturated fat to your diet. Instead of doing so, sprinkle the corn with your favorite herb or freshly-squeezed lemon juice. You can also try rubbing corn with lime wedge or sprinkling it with a chili pepper-type seasoning (6).
Given that the proteins in corn are incomplete, they certainly lack essential amino acids. To accommodate this, you should add nuts, legumes, dairy products or animal protein when preparing and serving corn (4).
Ferulic acid is a unique phytochemical that is mostly found in grains, fruits, and vegetables, but in very low amounts. However, corn has an abundant amount of ferulic acid. Cooking corn further increases the amount of ferulic acid significantly (4).
Points to Ponder
Corn on the cob, corn kernels, corn flour, and popcorn are widely available at grocery stores. These types of corn can be used in various dishes (3).
Corn is rich in fiber and plant compounds that may aid in digestive and eye health. When consumed in excessive amounts, however, this high-starch food can spike blood sugar levels and lead to weight gain (3).
To reap the most out of its unique benefits, consumer corn in moderation as part of a healthy and balanced diet.