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Four decades of nutrition research by the Centers for Disease Control and Prevention (CDC) is seriously flawed, according to a recent study published in PLOS ONE (The Public Library of Science). Nutrition data collected and reported over all those years based on survey results are not "physiologically credible," according to the study's authors.

The study examined data from 28,993 men and 34,369 women and looked at the daily caloric intake compared with the participants' energy expenditure, as predicted by height, weight, age and gender, according to a press release on the study. The vast majority of the self-reported data "are physiologically implausible, and therefore invalid," one of the study's authors asserted.

In other words, estimates of calories consumed across different groups within the U.S. population are skewed, meaning public policy related to diet and health taking these estimates into account is bound to be inaccurate. As National Journal's Brian Resnick noted: "From the survey, we learned things about nutrition that now seem so fundamental -- that diet and exercise choices are linked to body weight, that cholesterol is linked to heart disease, and so on."

This isn't the first time that health research has generated the wrong prescription for healthy living. In this slideshow, explore other good health advice that has, with further research, gone bad.

SEE ALSO: Unhealthiest Restaurant Meals in America: Photos

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What could be more fundamental to a healthy diet than the food pyramid? A guide first introduced by the United States Department of Agriculture in the 1990s, the food pyramid was ubiquitous, appearing on cereal boxes, milk cartons and more.

The original food pyramid was revised in 2005, to a diagram that provided even less accessible information about diet. The pyramid was entirely replaced in 2011 with MyPlate, which was met with a warmer reception, but left out key information such as the distinction between good and bad fats or proteins.

Harvard University's School of Public Health released its own MyPlate, with supplementary information on diet and exercise to fill in the gaps.

SEE ALSO: New Rules For Low-Calorie Diet

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For years, Americans have been told to watch their salt intake -- and for good reason. Too much salt in the diet can lead to dehydration, hypertension, cardiovascular disease, stroke and other negative health consequences.

Evidence has emerged, however, over the past couple decades that eating too little salt can also pose a health risk. As early as 1972, a paper published in the New England Journal of Medicine made the connection that "the less salt people ate, the higher their levels of a substance secreted by the kidneys, called renin, which set off a physiological cascade of events that seemed to end with an increased risk of heart disease," according to the New York Times.

SEE ALSO: Poor Eat More Hidden Salt, Suffer For It

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With everything going on during the week, whether you're at school or in the office, it's nice to take comfort in the fact that missing a few hours of sleep during the week can be easily made up over the weekend -- except for the fact that recent research is suggesting that might not be true.

A recently published study in the American Journal of Psychology found that trying to catch up on the weekends isn't enough to undo the damage done during the week, as reported by the Nashua Telegraph. Rather than trying to catch up on sleep after a bad night, the researchers recommended that poor sleepers instead should try to get back to normal as soon as possible.

SEE ALSO: Lack of Sleep Messes With Your Genes

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Vitamins are supposed to provide all the benefits of a well-balanced diet without actually having a well-balanced diet. A multi-billion dollar industry has in fact blossomed with this very promise.

An ever-increasing body of evidence, however, is casting skepticism on vitamins, suggesting they don't improve health outcomes at all and may even be downright harmful. A study published in 2004, for example, showed that excessive intake of vitamin E can increase risk of death. Another study, published in 2008, found that certain vitamins can increase lung cancer risk in smokers.

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We've all heard that we're not drinking enough water. Eight glasses a day, an oft-repeated health myth of unknown origin, isn't a number anyone needs to target. A recent national public health campaign spearheaded by First Lady Michelle Obama implores Americans just to drink more water without, as the Atlantic's James Hamblin notes, really specifying how much water anyone really needs.

According to the National Institute of Medicine, the average man needs to consume roughly 3 liters (about 13 cups) of total beverages a day. The average women needs around 2.2 liters (about 9 cups) of total beverages a day. That doesn't have to come from water, or even come entirely from liquid, as many foods we eat are also loaded with water.

The easiest advice for making sure you get enough fluids is simple: If you're thirty, drink something.

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What could be healthier than rising with the sun in the morning for a jog and/or an early day at the gym? Waiting until later in the day to do any physical activity, for starters.

Our bodies weren't meant for excessive physical exertion, according to researchers at the Sports Science Department at Brunel University in West London. They found that an early workout increases the risk of disease because the body's immune system cannot cope with exercise in the a.m.

The researchers recommended workouts in the evening, when levels of the stress hormone cortisol are lower and the body is better able to cope with the exertion.

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If you have a problem, just talk it out and you'll feel better. Right?

Wrong.

While talking through an issue might help with that particular problem, it certainly doesn't do much good for your health, according to research published in 2007 in the journal Developmental Psychology.

Venting is fine. Dwelling too much on a problem can lead to stress, anxiety, depression and other emotional and psychological issues, however, all of which can have a negative impact on physical well-being.