Nutritional concerns have changed in the last 15 years

Do any of us remember exactly what we were eating at the end of the last century, and why? The nutritional concerns and conventional wisdom that drive our dietary selections change over time. Some things that were a concern in 1999 are less so today. And there are many things we think about today that weren't even on the average person's nutritional radar back then.

When it comes to how we look at a healthy diet since the new millennium, here are five things that have now moved to the forefront.

1. Vitamin D. Vitamin D has been added to milk and to calcium supplements for years to aid the body's absorption of calcium. Now, research suggests that vitamin D may impact other health concerns. Vitamin D deficiency is now being linked to bone trouble, lower back pain, heart attacks and even depression.

The body produces vitamin D naturally when the skin is exposed to sunlight. It is also found in some foods such as fish, eggs, fortified soy and cereal products and meat products like salami and sausage. Still, recent studies have shown that 40 to 60 percent of people have some degree of vitamin D deficiency.

2. Energy drinks. There has been a proliferation of high-caffeine "energy drinks" since the turn of the century. Unlike traditional sports drinks, energy drinks don't mix well with exercise, however.

Beverages such as Gatorade and Powerade include water, salt and sugars in proportions that help the body absorb fluids and salts lost through exercise. Most are non-caffeinated.

Energy drinks, on the other hand, contain large doses of caffeine and other stimulants, which can lead to dehydration. They also contain a lot of sugar. The increasing popularity of these drinks among the young has raised concern about kids consuming such large amounts of caffeine at such an early age.

3. GMO foods. GMO stands for genetically modified organisms - crops that have had their genetic structure modified in some way, usually to make them more resistant to pests or to certain herbicides that farmers use to

control weeds. Although common, GMO foods have become controversial.

Potentially, plants could be modified to add very positive nutritional benefits; however, some worry that these "Frankenfoods" might ultimately cause harm to humans and to the environment.

4. Organic foods. While organic foods have been around for a very long time, their popularity was limited. Before 2000, they were usually found only in health food stores and co-ops.

Today, organic eating has become mainstream, largely fueled by concerns about pesticides and genetically modified foods. Now, you'll find organic foods in almost every grocery store and on lots of restaurant menus.

5. Omega-3 fatty acids. How we look at fat has changed. It's still considered good to limit our intake of fat, but modern nutritional wisdom recognizes that there are good fats and bad fats. Some fats, such as monounsaturated and polyunsaturated fats, are needed to maintain optimal health and to counter the harmful effects of saturated fats and trans fats.

Omega-3 fatty acids are often classified as "essential fatty acids." They are important for good health, but are not produced naturally by the body. We have to get them from the foods we eat.

Omega-3 fatty acids are found naturally in oily fish, nuts, and leafy green vegetables. They are thought to protect against heart disease, certain cancers, diabetes, and macular degeneration. They are critical for proper brain development and neurological function in developing babies, too.

Times change and new discoveries about health and the human body happen every day. Evolving scientific knowledge due to ongoing research, as well as changes in public policy and the marketplace provide both challenges and opportunities for all of us to stay well informed about nutrition. As we do, we can make better decisions about how our food choices affect our health.