Over the past 50 years, eating healthfully has become increasingly challenging. When our ancestors sat down to the table, their food had traveled far fewer miles, was fresher and, most important, was less processed. In addition, because our lifestyles are generally more sedentary, our daily intake requirements—currently between 1,800 and 2,000 calories—have decreased over this same time period.
Despite the abundance of information that’s available about calories, confusion abounds when it comes to the quantity and type of foods we should eat. Diets du jour such as Atkins, Jenny Craig, South Beach and the Zone are touted in the media as miracles that will make us skinny, fit and attractive. If only! Instead, the key to a successful diet is knowing the variety, type and amount of food that make up our daily nutritional needs. Creating menus with delicious, wholesome and nutritious food as their centerpiece requires an understanding of just a few simple components and concepts.
Aside from alcohols, the food we eat falls into three categories: carbohydrates, fats and proteins. Of foremost importance is knowing the proper amount of each that we should consume. Since we all metabolize food differently, health experts at the U.S. Department of Agriculture have established recommended ranges for optimum daily consumption:
- Carbohydrates: 45 to 65 percent
- Fats: up to 20 to 30 percent
- Protein: 15 to 20 percent
Carbohydrates produce energy for the body and come in two basic forms, simple and complex. Complex carbohydrates such as whole grains, legumes, nuts and vegetables take more time to digest, allowing us to feel fuller longer. They also contain more fiber and are generally the most nutrient-dense. Simple carbohydrates, also known as simple sugars, are found in dairy, sweets and fruits. While fruits and dairy provide vitamins and fiber, many of the simple carbohydrates are nutrient-vacant. Simple carbohydrates are digested more quickly, do not fill us up easily, and may lead to weight gain.
Found in all plants, this form of carbohydrate has the ability to attach itself to cholesterol-dense bile that gets excreted by the body. Available in two forms, soluble and insoluble, fiber is often insufficient in today’s diet, the tendency being to consume too much animal protein and not enough grains and vegetables. Of significant benefit to human health, fiber:
- Slows the release and digestion of sugars into the bloodstream.
- May decrease the risk of colon cancer.
- May lower blood cholesterol.
- Helps the body remove waste.
Often misunderstood as being harmful, fats actually insulate our body, cushion our organs, keep us warm and aid our immune system. That said, consuming too much fat, especially the wrong type, can lead to obesity, cancer and heart disease. All varieties of fats, including animal fats, nuts, seeds and vegetable oils, are differentiated by the manner in which hydrogen and carbon atoms interact with fatty acids. Nutrition science can be complex, but a simple approach is to realize that all fats fall into four categories:
Because they can raise HDL (“good” cholesterol) levels in the blood, monounsaturated fats are essential for a healthy diet and should be consumed more than any other type of fat. Olive oil, canola oil, avocados and some nuts, such as cashews and Brazil nuts, are good choices. Cold-pressed and expeller-pressed oil undergo the least amount of processing and tend to be the most nutritious.
Polyunsaturated fats have many of the same health benefits as their monounsaturated cousins. Soybean, safflower, sunflower and corn oil are all high in polyunsaturated fat. In addition, the omega-3 and omega-6 fatty acids found in salmon, mackerel, anchovies, flax seeds, walnuts and soy are polyunsaturated. Consuming these products acts to reduce the amount of cholesterol produced by the liver and may stimulate the immune system.
Of all the fats we consume, saturated ones are the most harmful and should be limited to 10 percent of total fat calories. Included in this category are butter, lard and tropical oils, all of which can increase levels of LDL.
Trans fats, such as those found in many processed foods, are solid at room temperature (as are many saturated fats). Practically speaking they work well for commercial baked goods and
fried foods. However, trans fats increase harmful LDL levels, can decrease good HDL levels and may be carcinogenic. It is best to avoid them.
Our bodies use proteins to grow, maintain systems and produce hormones, antibodies and enzymes. They also help transport oxygen, regulate and balance body fluids and are used as a backup energy source to carbohydrates. Sources of protein include animals and vegetables and are categorized as complete and incomplete. Humans require eight amino acids (complete proteins), which can be obtained from animal sources. Most legumes and grains contain incomplete proteins, which, when eaten together, become complete proteins. Soybeans, amaranth and quinoa are three vegetable sources that are considered complete proteins.