Obesity Weekly

A weekly update about some aspect of Obesity. Published Monday mornings

Posts Tagged ‘Fitness

Refined or Whole Grain?

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Increases in obesity rates correlate with increases in food portion sizes over time.  From 1910 to 1982 the average amount of food available for consumption remained within a range of 3000 to 3500 calories per day per person (1).  From 1982 to 2000 the calories available for consumption and the amount consumed increased in parallel by over 10%, or about 300 calories per day (1).  During the same time the rate of obesity went from 15-20% to approaching 30%.  For a dramatic visual of this effect see the map published by the CDC.  These data demonstrate the dramatic increase in obesity over time.  There are some really interesting data in the types of calories that are consumed.  The amount of carbohydrates consumed increased from just under 7 servings per day to almost 10 servings per day from 1970 to 2000.  Unfortunately, most of the carbohydrates were of the refined type, the least nutritious and satiating of the carbohydrates.  Examples of refined carbohydrates are white rice, white flour and white pasta.  If its white, its refined.  Whole grains still contain the outer bran and inner germ. The bran and germ contain fiber, B vitamins and antioxidants.  The white endosperm is the food supply for the developing seedling. Because it is supposed to support the rapid growth rate of the new seedling, it is calorie dense.  Whole grains tend to be darker in appearance and have more of a texture, or mouth feel, when eaten than the white variety.  Whole grains have a shorter shelf life than refined grains which explains why white is preferred by manufacturers.

Compare the nutritive value of white and wheat flour or white or brown rice (2).

nutrition-table2

One of the things that should be obvious from the nutritional chart is the decrease in dietary fiber, vitamins and minerals upon refining.  These nutrients are important and converting the product to a refined version is not in our interest as an informed consumer.  I think most understand that whole grains are more nutritive that refined grains, but still consumers prefer refined grains.  Why?  Is it because refined tastes better?  There have been only a couple studies actually testing this hypothesis.  It is one of the larger, untested assumptions in consumer America.  Ask any parent whether their child will prefer white bread to wheat bread, and the answer will most likely be white bread.  However, a study done by Zata Vickers at the University of Minnesota demonstrated that children either have an equal preference for white bread and wheat bread or that wheat bread was preferred (3).  In a follow-up study it was shown that participants liked Artisan bread, either white or whole grain, more than the bread made using standard production techniques (4).  Those participants who preferred white bread tended to like the white bread in the study.  Those who preferred refined bread cited familiarity and price as the significant contributing factors while those who preferred whole grain cited nutrition as a significant factor.  Reasons for preference including taste, texture, smell, freshness and convenience were not significant.  One of the novel aspects of this study was the use of 6-n-propylthiouracil (PROP) to assess the ability of the participants to taste bitter flavors.  The ability to taste PROP is genetically determined and those who are supertasters will avoid bitter food.  About 25% of the population are supertasters, 50% are medium tasters, and 25% are non-tasters. Interestingly, the supertasters were significantly averse to consuming whole grain bread, suggesting that some bitterness compounds in the unrefined flour contributed to the perceived bitter taste.

So about 1 in 4 people will have a real, biologic aversion to whole grain products.  3 out of 4 will have a small aversion or no aversion to whole grain products.  To assess which group you fall in, try a high quality whole grain bread to test if you can consume the product without an adverse taste.   If you really want to test whether your aversion to whole grain is due to the ability to taste bitterness, then you can have a friend give you samples in a blinded fashion, that way you don’t know what you are tasting and your expectations will not affect the results.  For the majority of the population, a good quality whole grain product is similar to a refined product in our perceived preference.  Since familiarity was a significant factor in the selection of a refined wheat bread, one just has to figure out which whole grain products they like.  There are a variety of options and choices and there is no nutritional reason to consume refined grain products when whole grain is better for you and when prepared in a preferred manner, a much more interesting and flavorful consumable.  And once the kids get used to it, they will continue a good nutritional habit as they mature.

1. http://ers.usda.gov/publications/FoodReview/DEC2002/frvol25i3a.pdf

2. USDA National Nutrient Database. http://www.nal.usda.gov/fnic/foodcomp/search/

3.Delk J, Vickers Z. 2007. Determining a series of whole wheat difference thresholds
for use in a gradual adjustment intervention to improve children’s liking of whole
wheat bread rolls. J Sensory Studies 22: 639-652.
4. Bakke and Vickers Journal of Food Science 2007

5.  For a complete nutritional comparison see the linked PDF file.

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Written by ecable

March 16, 2009 at 5:00 am

Posted in Health

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Welcome to Obesity Weekly

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Why a weekly blog about obesity?  Well this blog will discuss the various aspects of obesity, including social implications, novel research about the causes and potential treatments for obesity, helpful insights into lifestyle modification techniques and successful strategies used by others in their battle for a healthy lifestyle. The topic of obesity touches every individual in some way, whether it is a personal struggle, an empathetic reaction to a friend or loved one’s own battle with weight, or (God forbid) an annoyance with someone who is too big for the neighboring seat on the airplane.  It is clear that the first world is gaining weight compared with 20 or 40 or 100 years ago.  This phenomenon fuels a multibillion dollar industry from gadgets and pills to reality TV shows.  We will discuss the obesity-associated industry later, but perhaps the current media responsible for bringing the discussion of obesity to our livingrooms and water coolers is NBC’s The Biggest Loser.  In my opinion, it is one of the most inspiring reality television shows on the air since it demonstrates that lifestyle modifications result in dramatic decreases in weight and, more importantly, in increased fitness.  Although not much medical detail is shared about the biophysical changes that the contestants undergo, the show’s physician, Dr. Rob Huizenga, does collect quite a bit of data on each of the contestants.  In previous seasons contestants successfully controlled their blood pressure, asthma, and diabetes by decreasing weight and increasing fitness; some to the point of being able to eliminate certain medications altogether.

One of the oddities of the show is just how high the expectations become for weight loss week after week.  Hydration loss can give a dramatic weight loss for a short time, but is not sustainable week after week. And obviously, a 0 or 1 pound loss would be disappointing, considering all of the time spent exercising. But when contestants continue to lose 4-8 pounds per week, a half to one pound a day, there should be no reason for disappointment.  A weight loss at that rate is phenomenal.   This phenomenon clearly demonstrates our obsession with weight as an endpoint.  Perhaps more emphasis should be placed on the drastic medical improvements made by the contestants which are not just related to weight loss but also to increased fitness.

In the US, and in particular southern California, appearance is nothing short of an obsession.  Fat is considered unfit and ugly while skinny is seen as fit and pretty.  Unfortunately, skinny does not equal fit.  There is a a phenomenon called skinny-obese in which a person can be a normal weight but actually be obese on the inside.  All fat is not the same.  Fat under the skin, subcutaneous fat, is different than fat contained in the abdominal cavity.  While subcutaneous fat can be readily observed, visceral fat, which is the fat packed around the internal organs, the heart, liver, lungs and intestines, is impossible to observe from the outside. It is not completely understood why some people are more susceptible to visceral obesity although there are clearly genetic factors involved.

Visceral obesity is predictive of long-term adverse medical consequences.  The reason we should be concerned about weight should not be from a vanity perspective but from a health and wellness perspective.  Obese individuals have a greater risks of:

Medical Name Parameters affected Increased risk of: What you should know
Dyslipidemia Decreased HDL cholesterol

increased LDL cholesterol and triglycerides

Cardiovascular diseases including heart attack and angina Fasting lipid profile
Insulin Resistance/Diabetes Increased fasting blood glucose/insulin/glucagon impact on quality of life, dizziness, weakness, lethargy and eventually diabetes complications including blindness and amputation Fasting blood glucose and insulin
Acanthosis nigricans Dermatology disorder Increased awareness of appearance
Systolic blood pressure First number of the blood pressure reading Heart disease, heart failure, stroke, kidney failure Resting blood pressure
Focal segmental glomerulosclerosis (FSGS) Increased urinary protein, decreased plasma protein and decreased glomerular filtration rate Acute or chronic renal failure Urinalysis results and any signs of swelling around the hands or feet or around the face
Gallstones No available blood tests for gallstones per se but blood tests can assess infections or obstructions

Gallstones are diagnosed by imaging

Liver or kidney damage, pancreatitis and potentially much PAIN when passing a stone
Sleep Apnea Sleeping patterns Quality of life decreases – lethargy, heart disease, high blood pressure headaches and memory problems Your sleeping patterns.  Normally told to you by someone else.
Weight associated skeletal issues:

slipped capital femoral epiphysis

genu valga, tibia vara (Blount disease)

flat kneecap pressure/pain, flat foot

spondylolesthesis (low back pain)

scoliosis

osteoarthritis

Joint pain and musculoskeletal issues Quality of life and mobility decreases

Many of these associated conditions can be decreased or eliminated with proper weight loss and increased fitness.  As this weekly blog continues we will explore a variety of subjects based on obesity, everything from hard-core science to popular culture and strategies to improve fitness in yourself, your family and your friends.

Written by ecable

March 9, 2009 at 12:45 pm

Posted in Health

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