Food deserts are regions where people have limited access to healthful and affordable food. This may be due to having a low income or having to travel farther to find healthful food options. Show Without access to healthful foods, people living in food deserts may be at higher risk of diet-related conditions, such as obesity, diabetes, and cardiovascular disease. Several government bodies are now funding projects to prevent areas from becoming food deserts and to improve people’s access to food in existing food deserts. Keep reading to learn more about food deserts and how they impact health.
Food deserts are areas where people have limited access to a variety of healthful foods. This may be due to having a limited income or living far away from sources of healthful and affordable food. The United States Department of Agriculture (USDA) define a food desert as an area that has either a poverty rate greater than or equal to 20% or a median family income not exceeding 80% of the median family income in urban areas, or 80% of the statewide median family income in nonurban areas. In order to qualify as a food desert, an area must also meet certain other criteria. In urban areas, at least 500 people or 33% of the population must live more than 1 mile from the nearest large grocery store. In rural areas, at least 500 people or 33% of the population must live more than 10 miles from the nearest large grocery store. The USDA identified around 6,500 food deserts between 2000 and 2006. Experts estimate that around 23.5 million people in the U.S. live in low income areas that are farther than 1 mile to the nearest large grocery store. Of these people, 11.5 million have low incomes. A 2012 USDA report on food deserts suggests that regions with the following characteristics are more likely to become food deserts:
The report also notes that rural areas located in the West, Midwest, and South of the U.S. are much more likely to be food deserts than rural areas located in the Northeast. This may be because rural areas in the Northeast tend to be closer to urban areas containing grocery stores. According to the report, rural areas with growing populations may have a lower risk of becoming food deserts. Experts have not yet reached an agreement regarding the characteristics of the populations that live within food deserts. According to the 2012 USDA report, some research suggests that neighborhoods consisting primarily of low income minority ethnic groups have limited access to supermarkets compared with wealthier, predominantly white neighborhoods. The review also cites research suggesting that some low income neighborhoods have a greater number of grocery stores and live closer to these stores than wealthier people. In such cases, the issue may be the affordability of the foods rather than their proximity. In rural areas, the most important predictor of food access is lack of transportation. This means that people who do not have their own bicycle or vehicle and lack access to public transportation are more likely to lack access to healthful foods. Since researchers have not reached a consensus on the characteristics of the populations affected by food deserts, further investigations are necessary. Such investigations may help policymakers identify areas at risk of becoming food deserts so that they can implement better access to healthful foods. Maintaining a healthful diet involves: According to the 2015–2020 Dietary Guidelines for Americans, a healthful diet should include the following foods:
People living in food deserts may have limited access to supermarkets and other food retailers offering healthful and affordable foods. Even when convenience stores and small grocers stock healthful foods, they are often too expensive for people with a low income to afford. People living in food deserts may therefore be more reliant on food retailers or fast food restaurants offering a more affordable but limited variety of foods. The lack of access to healthful foods and easy access to fast foods may be linked to poor diets that are high in sugar, sodium, and unhealthful fats. This can contribute to diet-related conditions such as high blood pressure and cardiovascular disease. Some of the health effects of living in a food desert include:
Many food deserts also provide limited or unaffordable healthcare services. This contributes to negative health outcomes for people living in these areas. People use a number of terms to describe a population’s access to food. The sections below outline some other examples. Food swampsA food swamp is a region that provides adequate access to healthful and affordable food, as well as an overabundance of less healthful food options. In Canadian urban areas, food swamps are more common than food deserts. Food miragesA food mirage describes an area where people live close to grocery stores offering a variety of healthful foods but cannot afford those foods. Because of this, people must travel farther to find healthful foods that are within budget. Food insecurityFood insecurity refers to limited or insecure access to food because of financial constraints. Families and people with low incomes may not have enough money to afford healthful foods. Policymakers are actively looking for solutions to improve access to healthful foods in food deserts throughout the US. The Community Food Projects Competitive Grant Program fund sustainable food projects that help low income communities gain access to nutritious and culturally acceptable diets. These projects also address broader economic, social, and environmental issues surrounding the food system. Some of the issues that the Community Food Projects aim to address include:
Food deserts are areas where people are unable to gain access to healthful foods. They are a major issue affecting millions of people in the U.S. and around the globe. Experts suggest that living in a food desert may put people at increased risk of obesity, diabetes, and other weight-related conditions. Community Food Projects are working to improve food systems in food deserts. Their overall aim is to help increase residents’ access to healthful foods. Print this fact sheet by J. Clifford and A. Kozil** (9/17) Quick Facts…
CholesterolCholesterol is a waxy, fat-like substance found in all animals including humans and is essential to every cell in the body. Cholesterol is used to make certain hormones, like estrogen and testosterone, and it is part of a chemical called bile, which helps to digest fats. A special form of cholesterol found in the skin has the ability to change into vitamin D when exposed to sunlight. There are two different types of cholesterol:
How is blood cholesterol transported by the body? Cholesterol is transported in the blood by different carriers. The relative amounts of cholesterol transported by each carrier can affect one’s risk for heart disease. The two major blood cholesterol carriers are LDL (low density lipoprotein) and HDL (high density lipoprotein). LDL cholesterol is known as “bad” blood cholesterol, and functions to deliver cholesterol to cells throughout the body and can be deposited as “plaque” on artery walls. HDL cholesterol is known as “good” blood cholesterol, and functions as a vehicle in the blood to remove cholesterol waste from the body via the liver (Table 1).
Where do we get cholesterol? Our bodies have the ability to make all of the cholesterol needed for proper functioning once we reach childhood, but most people also get cholesterol from foods. Different foods vary in the amount of cholesterol they contain. Only animal products have cholesterol; plant based products may contain fat, but they do not contain cholesterol. Is cholesterol harmful? Cholesterol is necessary for a healthy body, but a high blood level of total cholesterol is a major risk factor for atherosclerosis (hardening of the arteries), heart disease, and high levels of LDL cholesterol. The risk continues to increase as blood cholesterol levels elevate. For more information on cardiovascular disease, see fact sheet Heart Health: Managing Heart Disease through Diet. While the 2010 Dietary Guidelines for Americans recommended limiting consumption of dietary cholesterol to 300 mg per day, this recommendation is not included in the updated 2015-2020 edition of the Dietary Guidelines. This change reflects new research that suggests that dietary cholesterol, consumed in moderate amounts, does not affect health risks, including heart disease, for the majority of people unless a person has diabetes. Consuming solid fat (saturated fat), not cholesterol, is what increases heart disease risk for most people. Still, the healthy eating patterns highlighted in the 2015 Dietary Guidelines contain approximately 100 to 300 mg cholesterol per day, in keeping with the previous 2010 recommendations. The Institute of Medicine also recommends individuals eat as little dietary cholesterol as possible as a part of a healthy eating pattern. In general, foods that are higher in dietary cholesterol, such as fatty meats and high-fat dairy products, are also higher in saturated fats.
The National Cholesterol Education Program (NCEP) recommends a blood test known as a “lipoprotein profile” every five years for those ages 20 and older. This test reveals information about the total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride levels in the blood (Table 2). Triglycerides are also a type of fat found in the blood. The results of the blood test, along with other factors such as age, gender, family history, smoking, hypertension, diabetes, and obesity, can help determine one’s overall risk for heart disease. FatsWhat is dietary fat? Fat is a necessary component of a healthy diet. It is a part of every cell in the body and makes up about 60% of the brain. Fat is essential in the absorption of fat-soluble vitamins A, D, E and K and also makes up parts the hormones that regulate important body functions. Dietary fat provides essential fatty acids, such as linolenic (omega-3) and linoleic (omega-6) acids, which the body cannot produce on its own. Essential fatty acids are necessary for brain and eye development in infants and children and the maintenance of healthy skin in children and adults. Dietary fat may improve the taste of food, aid in cooking, and increase satiety. Yet, eating too much fat may lead to increased weight, as it has more than twice as many calories per ounce as sugar, starch or protein. Consuming fatty foods in excess may increase total and LDL cholesterol levels, while increasing the risk of heart disease and some forms of cancer. Types of FatAre all fats the same? There is not a single type of fat. Rather, the word “fat” is often used to refer to all of the fatty substances found both in food and in the body. Lipids: Scientific term referring to fat, cholesterol and other fat-like substances. Triglycerides: Scientific name for the main form of fat found in in the body and in foods. Most of the fat in the body is stored as triglycerides, but triglycerides circulate in the blood as well. Triglycerides are made of three fatty acids and one glycerol molecule. These three fatty acids may include any combination of saturated fatty acids, monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs). Triglycerides in the blood stream trigger the liver to make more cholesterol, so high triglyceride levels are often associated with high levels of total and LDL cholesterol. Saturated Fat Acids (SFAs): Usually solid at room temperature, saturated fats have all of the hydrogen atoms they can hold (saturated with hydrogen). Saturated fats are primarily from animal products, but are also found in tropical plant oils, such as coconut and palm as well as other plant based foods, though in smaller amounts. The 2015 Dietary Guidelines for Americans suggests limiting saturated fats in the diet to less than 10% of daily calories. See Table 3 for the health effects of saturated fats in the diet. Monounsaturated Fats (MUFAs): Liquid at room temperature, monounsaturated fats are missing one pair of hydrogen atoms. Monounsaturated fats are primarily derived from plants and include olive oil, canola oil, peanut oil, and avocados. See Table 3 for the health effects of monounsaturated fats in the diet. Polyunsaturated Fats (PUFAs): Liquid at room temperature, polyunsaturated fats are missing two or more pairs of hydrogen atoms. Many common vegetable oils, such as corn, soybean, safflower and sunflower oil as well as fish are high in polyunsaturated fats. See Table 3 for the health effects of polyunsaturated fats in the diet. Essential Fatty Acids: Fatty acids that are essential to human health but not produced in the body must be obtained through food. Only two types of fatty acids are considered essential; omega-3 fatty acids and omega-6 fatty acids, both polyunsaturated fats. The 2015 Dietary Guidelines for Americans emphasize vegetable oils (mono- and polyunsaturated fats) as part of healthy eating pattern because they are the major source of essential fatty acids and vitamin E.
Hydrogenated Fats: These are unsaturated fats that are processed to become solid at room temperature. Hydrogen atoms are added to unsaturated fat through a process called hydrogenation. This turns unsaturated fats into saturated fats. Hydrogenated fats can either be fully or partially hydrogenated, and are used in foods to enhance texture, extend shelf life, and prevent rancidity. Packaged and processed foods such as cookies, crackers, and margarine most commonly contain these types of fats. Trans Fatty Acid: Trans fats occur naturally in some foods derived from cattle and sheep, but generally, this type of fat is formed during the process of hydrogenation. Only partially hydrogenated fats contain trans fats, where fully hydrogenated fats do not. Trans fatty acids mimic the properties of saturated fats in the body, and have been shown to increase LDL cholesterol and lower HDL cholesterol, which may increase the risk for heart disease. The 2015 Dietary Guidelines for Americans suggest limiting trans fats in the diet. Trans fat may be found in partially hydrogenated margarines, peanut butters, and snack foods. In 2015, the Food and Drug Administration (FDA) stated that partially hydrogenated oils were no longer recognized as safe for use in foods, as they are the primary source of dietary trans fatty acids. The food industry was given 3 years to comply with the ruling and remove TFA’s from food products.The FDA stated that removing partially hydrogenated oils from processed foods could prevent thousands of heart attacks and deaths each year.
The Relationship Between Fat and CholesterolHow are fats related to blood cholesterol? Research shows that the amount and type of dietary fat consumed can affect blood cholesterol levels. Dietary fat, especially saturated and trans fats, may raise blood levels of total and LDL cholesterol. Replacing some saturated fats with polyunsaturated and monounsaturated fats (especially olive and canola oil) can help lower blood cholesterol. Recall that high total blood cholesterol levels and LDL cholesterol levels increase risk of heart disease, while lower levels reduce risk. Higher levels of HDL cholesterol help lower the risk for heart disease. What foods contain fat and cholesterol? In some foods, fats are obvious, like noticeably greasy, fried or oily foods, or meats with visible marbling. In other foods, such as dairy, eggs, and some meats, fat and cholesterol is harder to see. Fats are found in both plant and animal foods, but cholesterol is only found in foods of animal origin. A food can be high in fat and cholesterol (fried egg), high in fat but low in cholesterol (peanut butter and avocado), low in fat and high in cholesterol (shrimp), or low in both (fruit). The nutrition facts label is a useful tool to determine the amount of fat or cholesterol in a particular food item. Monitoring Intake of Fat and CholesterolDietary fat and cholesterol are necessary components for a healthy diet. Though, when consumed in excess, they may be harmful to the body and increase one’s risk for obesity, atherosclerosis, and heart disease. Keep in mind, however, that dietary cholesterol does not have as much of an effect on blood cholesterol as saturated fat. It is important to regulate ones intake of dietary fat in order to regulate blood LDL, HDL, and triglyceride levels. Summary
ReferencesAdvanced Nutrition: Macronutrients, Micronutrients, and Metabolism (2009). Boca Raton, FL: CRC Press, Taylor & Francis Group. Duyff, R. L., Academy of Nutrition and Dietetics. (2017). Complete Food and Nutrition Guide 5th Edition. New York, NY: Houghton Mifflin Harcourt Publishing Company. Mahan, L. K., Escott-Stump, S., Raymond, J. L., & Krause, M. V. (2012). Krause’s food & the nutrition care process. St. Louis, Mo: Elsevier/Saunders. United States Department of Agriculture. (2016). 2015 Dietary Guidelines for Americans. Retrieved from: http://health.gov/dietaryguidelines/2015/guidelines/ *J. Clifford, Colorado State University Extension food and nutrition specialist , A. Kozil, graduate student. Original fact sheet revised by L. Bellows, Colorado State University Extension food and nutrition specialist and assistant professor; and R. Moore, graduate student. 5/96. Revised 9/17. Colorado State University, U.S. Department of Agriculture, and Colorado counties cooperating. CSU Extension programs are available to all without discrimination. No endorsement of products mentioned is intended nor is criticism implied of products not mentioned. Go to top of this page. |