Nutrition Myth and Logic

Nutrition Myth and Logic

Our body uses a mix of fat and carbohydrate to fuel the energy needs of our cells. Researchers can quantify this mix with high accuracy in an exercise physiology laboratory using expired gas analysis. The percent contribution of fat and carbohydrate does indeed vary depending on the intensity of exercise.

For instance, when we transition from rest to exercise, there is an increase in energy expenditure (i.e., calories burned) to meet the increased needs of our muscles. When the exercise is of a low intensity, our bodies preferentially use fat as a fuel, similar to a resting state. Thus, low intensity exercise does predominantly rely on fat to fuel contracting muscles.

As the exercise intensity increases, added neural stimulation, hormone concentrations, and a complex regulation of muscle metabolism causes a progressively increased dependence on carbohydrate catabolism. The greater the increase in exercise intensity, the greater the dependence on carbohydrate until eventually only carbohydrate is used by muscles to fuel contraction.

Of course 20 years ago the above statements would have been laughed at. While we’ve learned a lot about health issues here over the years, we can’t claim expertise on any particular subject. That said, we want to point out a few myths that are still lingering.

MYTH 1: EATING FATTY FOOD MAKES YOU FAT
It seems obvious that fat makes you fat, but what seems obvious often turns out to be wrong. After all, we used to believe geese grew on trees for reasons that actually made some sense. Just because fat goes into our body doesn’t mean it stays there, however, and so we’ve now found that a long-held assumption didn’t make a lot of sense.

Eating fatty foods does not make you fat. Fat in moderation is a necessary part of any healthy and balanced diet. Putting on more weight in the form of fat is a result of energy imbalance. You will gain weight if you take in more calories than you burn. Fat is a concentrated source of calories, but it is not necessary to eliminate fat from your diet completely.

Whole-food fats (nuts, seeds, avocado) are satiating and help you feel fuller for a longer period of time. You can’t put French fries and almonds in the same category simply because both are “high in fat.”

Fat can make you fat, but so can carbohydrates and (to a much lesser degree) protein; it just matters that you over-consume the source of calories. Granted some fats are seen as ‘better’ than others (such as coconut oil and fish oil relative to trans fats) which accounts for some variability in weight gain, but weight gain will occur when ‘excess’ is consumed (whatever that may be to your body).

FAT WON’T MAKE YOU FAT,
UNLESS YOU EAT TOO MUCH OF IT

You know, like anything else. You have to beware of fat free, as well, as it often actually contains fat and adds quite a bit of sugar. When something gets eliminated, make sure to find out what filled the void.

MYTH 2: EATING CARBS MAKES YOU FAT
If eating fat won’t make you fat, carbohydrates must! Right? Carbs, the devil of our current decade, get cut from just about every new fad diet to promote super fast fat loss. Again, the truth comes down to striking a healthy balance.

While it is becoming more popular to blame carbohydrates as the cause of obesity, people don’t realize that de novo lipogenesis (DNL; which converts sugars into fat) tends to be inefficient in human bodies. For carbs to make one fat, they would need to work in concert with a poor diet and lack of exercise which makes those latter two more readily blamed.

SO HOW DO YOU TELL WHEN CARBS CAUSE PROBLEMS?
More over-simplified nonsense. Again, a Pop-Tart (carbohydrate-rich) and a pear (also carbohydrate-rich) are not the same thing. The problem is refined and highly processed carbohydrates, which can trigger cravings.

It is a good idea to limit the number of carbs you eat in the form of sugar because sugar is low in nutritional value and high in calories. However, if you eliminate carbs completely, you will miss out on healthy food such as whole grain breads and wheat pastas. You will only gain weight if you consume more calories than you burn.

PERHAPS YOU’RE SEEING A PATTERN HERE
A healthy diet comes down to balance and choosing natural sources of carbs when you include them. You don’t have to eliminate them entirely, but focus on the options with greater nutritional value and limited processing.

MYTH 3: HIGH-FRUCTOSE CORN SYRUP IS WORSE THAN SUGAR
High-fructose corn syrup (HFCS) gets a bad rap. Make no mistake—it’s bad, but compared to sugar you won’t find a huge difference in the overall impact to your health.

The content of fructose in both options (sucrose and HFCS) are pretty much similar, and if you ate enough HFCS for the extra 5% to matter then you over-consumed any type of sugar. There are no other known differences between these two sugars, and that one Princeton study saying otherwise has not only failed to have been replicated but is more than likely just misleading data.

It’s technically no different, but it’s ubiquitous, takes a huge toll on the environment, and is a marker for highly processed foods.

As you may have noticed so far, a lot of stuff we consider problematic in our diets doesn’t cause as much trouble as we believe on its own but rather has a negative impact due to where you’ll find it. HFCS, carbohydrates, and fat often appear in highly processed foods. We think of them as bad because they exist in many unhealthy meal options and show up places where they don’t necessarily belong. Rather than demonize an ingredient, we need to focus on the food as a whole. You won’t find much good stuff in HFCS or sugar, but you’re more likely to find sugar in nutritious options and HFCS injected into foods that don’t need it.

MYTH 4: GLUTEN-FREE FOODS ARE HEALTHIER
The gluten-free craze recently took hold and you’ll find tons of options as a result. Will you benefit from eating them? That depends on what your specific body needs. Just because some people need to eat gluten-free doesn’t mean it will work for you.

If you are celiac or gluten sensitive, gluten is problematic. Otherwise, the body is technically able to process gluten. The absence of gluten in a food does not automatically make it healthier (soda is gluten-free). A lot of gluten-free breads are made with refined starches, which are not healthful. While I think many people can tolerate gluten just fine, I also don’t get concerned if someone tells me they feel better when they don’t eat it. Shunning gluten from your diet doesn’t put you at any sort of nutritional risk.

GLUTEN-FREE FOODS ARE ONLY HEALTHIER
FOR YOU IF YOU ARE ALLERGIC TO GLUTEN

If you aren’t, eating a gluten-free diet restricts the amount of fiber, vitamins, and minerals you are able to consume. A variety of foods that are high in whole grains (such as foods containing wheat, rye, or barley) also contain gluten, and these foods are an essential part of a healthy diet. Most people have no trouble digesting gluten.

WHY DON’T MOST PEOPLE HAVE DIFFICULTY DIGESTING GLUTEN?
Unsurprisingly, people get duped when they meet celiacs whose lives improved vastly by cutting out gluten. Naturally, since they can’t process the stuff, that would happen. Few of us suffer from celiacs disease, fortunately, so we can handle products with gluten. Like with everything else, however, eat it with balance in mind.

MYTH 5: EVERYONE NEEDS TO POOP DAILY
Some talented, amazing people can poop twice a day. How do they process that much waste? It must be magic. If you don’t make a bowel movement daily, it can seem like a problem when you compare yourself to those who take more frequent toilet breaks. Fortunately, you don’t have to worry. Everybody poops, but schedules vary.

NO SINGLE BOWEL MOVEMENT SCHEDULE IS RIGHT FOR EVERYONE
However, staying hydrated, eating foods high in fiber, and being active will help ensure that your schedule is regular and you do not become backed up.

REGARDLESS OF HOW WELL YOU EAT, YOU SHOULDN’T EXPECT A PREDICTABLE SCHEDULE:
The frequency of defecation is not something that should be put to a schedule, since it is a bit unreliable and dependent on food intake. Consistency of the stool, perhaps assessed by the bristol stool chart, is more reliable of an indicator of health than the frequency; while altering frequency does affect the body, it shouldn’t be a major concern unless you get constipated or cannot function due to frequently watery defecations.

IF YOU DON’T POOP FREQUENTLY, DON’T WORRY.
Make sure your stool appears healthy and that it doesn’t cause you discomfort. Beyond that, you don’t need to worry much about your poop.

REMEMBER: WE STILL DON’T KNOW EVERYTHING
We still don’t know a lot about our health. Science often makes new discoveries and we learn a bit more, but we also run into several instances where new studies can get taken out of context by the news and myths—much like the ones in these posts. That said, you can only go on the best information currently available.

Before you start worrying too much about what you eat or how you take care of yourself due to something you’ve heard or read, make sure you do the research and consult professionals. Often times the myths that propagate throughout our society take hold because they seem logical and reasonable, but science doesn’t back them up. Hopefully we’ve dispelled some good ones for you here today, but you’ll always find more. Remember to always keep learning, and that few health answers are definitive at this time.

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2 thoughts on “Nutrition Myth and Logic

  1. Nice work! Although there is some evidence that HFCS is worse for people than sugar. http://www.ncbi.nlm.nih.gov/pubmed/22152650 is an example. How much is debatable, but I would not be so dismissive. More research needs to be done for sure, but the obesity trend coincides with HFCS use and there will likely soon be evidence that many sweeteners, including HFCS, either alter the palate or satiety leading to this trend. Nonetheless, I thought the blog was very good. Thanks for sharing.

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