Monday, June 14, 2010

9 NUTRITION MYTHS EXPOSED

9 Nutrition Myths Exposed
By Joe Wilkes (edited by P.Duvall)

Every fall, the publishing industry begins a new cycle of hitting bookstore shelves with diet books, just in time to help assuage winter holiday guilt and prepare for New Year's resolutions. At the same time, TV stations are in the throes of sweeps periods and launching a new season. You know this phenomenon is in full swing when you start hearing the local news and talk show pitches: "You can lose 10 pounds in 1 week and eat whatever you want!" or "A common ingredient in your kitchen that will burn off fat without exercise! Tune in at 11 to see what it is!" Then in the next media cycle there'll be new books and news stories telling us how these miracle cures were all a load of hooey, but there are brand-new miracle cures that really work! Here are some common nutrition myths that have gone in and out of fashion over the years—and the real truth behind the hype.

Myth #1: Fat makes you fat.

People confuse dietary fat, the fat that we eat, with body fat, the adipose tissue that makes up our spare tires and thunder thighs. But while it's true that dietary fat contains twice as many calories per gram as carbohydrates and protein, what actually makes us fat isn't the dietary fat, it's the calories in that fat. In fact, the calories in the carbohydrates and the calories in the protein can also make us fat. Dietary fat is very important to human health, and should make up around 25 to 30 percent of our caloric intake. For one thing, fat helps with the absorption of several vitamins that are only fat soluble, including vitamins A, D, E, and K. Fats also include heart-healthy omega-3 fatty acids. Artery-clogging saturated fats and trans fats should be mostly avoided though, as they will raise blood cholesterol levels (see #2) and clog arteries with plaque.

In the 1980s, fats became vilified by regulatory and health agency reports as being unhealthy overall. The reasoning was that while the agencies were largely targeting saturated fats (as found in animal and dairy products), they believed it would be simpler to tell Americans to avoid all fats instead of having to explain the complexities of saturated, unsaturated, monounsaturated, polyunsaturated, hydrogenated fats, etc. Because of these warnings, the food industries began marketing scores of low-fat or fat-free versions of products. In many cases, they would replace the missing fat with sugar or starch. So while there would be less fat, there would be almost as many—and sometimes more—calories. Consumers would eat twice as many of the new "reduced-fat" treats and wonder why they weren't losing any weight.

As more studies have come out extolling the benefits of healthy unsaturated fats, like those found in olive oil, avocados, nuts, fish, etc., more specific recommendations have been made to increase the allowance of good dietary fats while decreasing the allowance of saturated and trans fats. In fact, many makers of cookies, breakfast cereals, and snack chips now trumpet "No Trans Fats" on their packaging. That's great, but don't be fooled into thinking this means there are any fewer calories. Just because the manufacturer has shown restraint in not making the food even unhealthier doesn't mean that it's suddenly health food. Some of these "No Trans Fats" products never had trans fats to begin with, but it's good marketing to proclaim it. Now poison free! Not quite as toxic! Just as fattening with less artery plaque! For your health, check the labels and make sure that the kind of fat in the product is unsaturated—and make sure there aren't too many calories for your waistline. A day's dietary fat intake should be around 60 to 70 grams.

Myth #2: Foods high in cholesterol give you high cholesterol.

As with dietary fat, foods with high dietary cholesterol levels are believed by many to raise blood cholesterol levels. High blood cholesterol levels have been linked to heart disease and stroke, and levels should be monitored. However, our bodies need some cholesterol for normal cellular function and to assist in the production of bile, which helps the body digest fat. Unfortunately, because dietary and blood cholesterols have been given the same name, people take an attitude of "cholesterol in, cholesterol out." In fact, studies are increasingly showing that high blood cholesterol comes from a diet high in saturated fats, while foods high in dietary cholesterol have a fairly negligible effect on high blood cholesterol. Foods high in dietary cholesterol but low in saturated fat, including eggs, shrimp, lobster, crab, clams, and other shellfish, can be safely eaten in moderation without having much effect on blood cholesterol levels. Where this misunderstanding of the causal link between dietary and blood cholesterol levels may have also come from is that many non-seafood animal products contain high levels of dietary cholesterol as well as high levels of saturated fat. So if double cheeseburgers are making regular appearances in your diet, you're going to see a spike in your cholesterol score—but it'll be from the saturated fat.

Myth #3: Snacking will cause weight gain.

Isn't this what Mom always said? "No snacking or you'll ruin your appetite!" Good! Go ahead, ruin your appetite! If you ruin your appetite, you won't eat so much dinner. Nutrition experts have pretty much come to a consensus that you're much better off having six small meals over the course of the day than two or three giant meals. You'll give your body a steady source of fuel and keep your blood sugar levels and metabolism at an even keel all day long. If you think back to our caveman days, before we sat down to eat civilized meals, we probably just wandered the forests and jungles, eating when we were hungry or when the opportunity arose. Those instincts are worth listening to today. If you have a hunger pang at three o'clock in the afternoon, don't stifle it because you know you're having dinner at seven. You'll be so hungry, you'll approach dinner like maniac, eating way more than you would have if you had merely satisfied your afternoon hunger with a piece of fruit or a handful of nuts. Keep in mind though, permission to snack isn't permission to stuff your face with Doritos, Fritos, Cheetos, or any other kind of "-tos." There should be some sort of strategy to the snacking. Try evenly pacing out the snacks and predetermine a reasonable portion size of a healthy food, so you're not just eating handfuls of something out of a bag.

Myth #4: If you exercise enough, you can eat whatever you want.

How many times have you heard your horrible friends who never gain weight say, "Oh, I'll just run it off" to justify whatever sinful treat would give you a third buttock if you ate it? It's impossible to keep a fit, healthy figure without both a healthy diet and exercise. It's all right to indulge in the occasional pig-out sometimes. In fact, it's good to reassure your body that there's no need to go into starvation mode from time to time. But if you eat that slice of blackout cake, you're looking at a 2-hour run just to burn it off, let alone what came before it. Losing weight and maintaining weight is a simple equation: if you burn off more calories than you take in, you will lose weight. Some lucky stiffs have a higher resting metabolism and burn off more calories naturally, but what probably helps your friend burn off the cake faster is that they have more muscle on their body, and, even at rest, muscles burn more calories. So while you can never eat whatever you want and stay thin, you'll be able to indulge in a pig-out every once in a while if you can keep your body muscular and lean. And for those times, you might consider trying exercise program designed to burn more calories than walking or running, which will help you maximize the calories you burn in the time you spend exercising.

Myth #5: Drinking lots of water flushes out fat.

Drinking plenty of water is vital for weight loss. If you're dehydrated, your energy and exercise will suffer. Also, many times we confuse thirst for hunger, so it's always worth trying a glass of H2O before we hit the fridge. Drinking water can even give your metabolism a slight boost. What it doesn't do is flush fat from your system. Any excess water that your body doesn't need for proper hydration and functioning will simply get peed out, and, sadly, it won't be taking any fat with it. You should definitely make sure you drink enough water, but don't go overboard thinking you can chug away your love handles. If you drink too much water at any one time, it could even result in hyponatremia, or water intoxication. However, adult kidneys can process 15 liters of water a day, so drinking too much water day to day is unlikely. (It's more likely if you're involved in extreme Ironman-type athletic activities where over- and under-hydration are real possibilities.) Keep a water bottle handy and drink when you're thirsty, but if you really think you can flush away your belly, you may need to think again.

Myth #6: Multigrain bread is better than white bread.

While whole-grain bread is better than white bread, multigrain bread is only better if the grains are whole grains, which isn't always the case. With the bread industry, it's really important to check the ingredient list carefully. For example, "wheat bread" is just white bread with molasses added for color. So, if anything, it's worse for you than white bread. Unless it says "whole-wheat" bread, you're not getting the added fiber and nutrients that come with using whole grains as ingredients. Many multigrain breads are just processed-flour breads upon which manufacturers sprinkled a couple of sunflower and sesame seeds. Hey, that's two grains, right? That makes it multigrain! So even if the headline on the packaging says "whole-grain," double-check the ingredient list to make sure all the grains, or at least the tmain ones, are whole. Similarly, many breakfast cereals have switched to whole-grain flour, but if the cereal still contains more sugar than a candy bar, it's not going to move the needle much toward better health. Try to find whole-grain brands with minimal or no sweetening. If you need to, you can always add your own sugar, and at least control the amount you consume.

Myth #7: Sugar causes diabetes.

Many people falsely assume that because diabetics have to watch their sugar and carbohydrate intake that sugar causes diabetes. But if you don't have diabetes, sugar won't cause you to get it. The main risk factors for type 2 diabetes are being overweight and being inactive. As with fat and cholesterol, blood sugar and dietary sugar are often confused. If you eat sugar, you won't necessarily get diabetes, but sugar is highly caloric and, as part of a high-calorie diet, can be a contributing factor to obesity, which does have a causal link to type 2 diabetes. This isn't to say that it's okay to eat lots of sugar, but it's good to be aware that if you have a high-calorie diet, you are still just as much at risk for diabetes, even if that high-calorie diet doesn't include a lot of sugar. As with most dietary health issues, it's mainly about the calories.

Myth #8: Grapefruit burns fat.

Anyone who remembers the heydays of the Hollywood or Beverly Hills diets knows that they were good times to invest in grapefruit futures (as well as other "miracle" fruits and vegetables). The theory of those and similar diets was that grapefruit had a secret enzyme that would make body fat disappear. Grapefruit is a very healthy citrus fruit and worth eating as part of a varied diet. It has tons of vitamin C and can help fight arterial plaque buildup, and maybe even certain kinds of cancers. But grapefruit can't burn fat. Cabbage soup can't burn fat. Celery can't burn fat. In fact, no food can. Some foods can temporarily increase your metabolism to assist your exercise efforts in fat loss, but the only way to truly burn fat is through exercise. And, if any fad diet revolves around a secret fat-burning ingredient, that should be a red flag that the diet isn't nutritionally sound. Not to sound like a broken record, but the only way to effectively lose weight is to eat fewer calories and burn off more calories through exercise. Healthy metabolism-boosting foods can help, but they can't do it alone.

Myth #9: Light olive oil has fewer calories than olive oil.

If you read the labels of various olive oils, you'll notice that light olive oil has pretty much the same amount of calories as any other kind of olive oil. The difference is in the flavor. Light or extra-light olive oil has been heavily processed to remove the strong flavor of olive oil and make it lighter in color. It may even have been combined with other vegetable oils to achieve a milder taste and color. It still has just as much fat and calories as extra-virgin olive oil, but not nearly as many nutritional benefits, including vitamin E and polyphenols. Unlike extra-virgin olive oil, light olive oil is an unregulated product, so you don't know what you're getting.

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