Human Nutrition 2004:
Food Pyramids, Carbs and Calories
February 4 or Feb 11, 2004

Readings: Rebuilding the Food Pyramid, By Walter C. Willett and Meir J. Stampfer. Scientific American, January 2003 (full version; printer friendly version)
Don't forget...Warm Up 4 is due Weds Feb 11 at 9:30 and Good For 4 at 11:30 Friday Feb 13!

Why is there so much information - often conflicting - about nutrition? Currently (depending on the website, TV show, or book you might be reading) we are told that it is best to "eat lots of meat, don't eat any meat, eat lots of carbohydrates, don't eat any carbohydrates, cut your intake of fat to under 20 percent of calories, increase fat intake to 60%, stay away from sugar, eat potatoes....". Added to this are the stories about good foods gone bad...Tuna with high mercury, cows with spongiform encephalopathies, oreos with trans-fats, genetically modified soybeans.....yikes! What is sound nutrition and what is not? We can't cover all the bases in N100, but here's some information that YOU can use as a start to evaluating how you eat now and how you might like to eat and modify your lifestyle in the future. Keep in mind that your instructor, Dr. Marrs, is not a nutritionist, a dietician, does not have any ties, financial or otherwise, to any particular method described below, and is frequently seen tossing oreos into her mouth on her way to N100....

SO...Lets start with the Biggie:
I. The current 1992 Food Pyramid: Summary: "All fat is bad, all carbs are good": In 1992 the USDA "Food Guide Pyramid" was released, which was intended to help the American public make good dietary choices that would maintain health and reduce the risk of chronic disease. The recommendations embodied in the pyramid soon became well known:

• Six to 11 servings a day of foods rich in complex carbohydrates--bread, cereal, rice, pasta
• Minimize their consumption of fats and oils to no more than 30% of total calories
• 5-a-day for vegetables (potatoes were included here) and fruit
• 2-3 servings of dairy products
• 2 or more servings a day from the meat and beans group, (red meat, poultry, fish, nuts, legumes and eggs).

As a result, the USDA recommends that the average American diet for a person ~150 pounds (~2000 calories/ day) consist of

• 65g Total Fat (20 g of which can be saturated fat),
• 300 mg or less of cholesterol,
• 2400 mg of sodium
• 300 g of carbohydrate (25g of which should be fiber...aka cellulose)
• ~65 g protein (varies depending on weight)

HOWEVER, it is well accepted today that the USDA's 1992 food pyramid over-simplified the picture for consumers, in an attempt to make it 'easier' for consumers to make wise food choices. Walter Willett, chairman of the Nutrition Department at Harvard University, is one of the many MDs who takes issue with the current food pyramid. for nutritional reasons as described in today's readings. (also see THE HOLES IN THE USDA PYRAMID - scroll down in article - for a nice summary) Specifically, the food pyramid failed to stress the important health differences between different foods:

• Red meat (beef, pork and lamb; can be high in saturated fat and cholesterol) vs. the other foods lumped into in the meat and beans group (poultry, fish, legumes, nuts and eggs).
• Good fats (polyunsaturated and monounsaturated) vs. bad fats (saturated and hydrogenated)
• Whole grain complex carbohydrates (fiber, nutrients) vs. refined white flour carbohydrates (white bread, rice, and potatoes - glucose polymers that raise blood sugar levels as quickly as - or even quicker than - eating candy or table sugar!)

Who developed the Food Pyramid? Willett, many scientists, as well as the legal system, also takes issue with who developed that food pyramid: [Quote] "The thing to keep in mind about the Food Guide Pyramid is that it comes from the USDA, responsible for promoting American agriculture, not from agencies established to monitor and protect our health, like the Department of Health and Human Services, or the National Institutes of Health... And there's the root of the problem--what's good for some agricultural interests isn't necessarily good for the people who eat their products. Serving two masters is tricky business, especially when one of them includes persuasive and well-connected representatives of the formidable meat, dairy, and sugar industries. At best, the USDA Pyramid offers indecisive, scientifically unfounded advice on an absolutely vital topic--what to eat. At worst, the misinformation it offers contributes to overweight, poor health, and unnecessary early deaths."

But did the USDA actually do anything unethical in setting the food pyramid, or is this just another one of those Dr. Marrs conspiracy theories? Well, as a matter of fact...October 2, 2000: Court Rules Against USDA's Secrecy and Failure to Disclose Conflict of Interest in Setting Nutrition Policies " The U.S. Department of Agriculture violated federal law by keeping secret certain documents used in setting federal nutrition policies and by hiding financial conflicts of interest among members of a diet advisory committee, U.S. District Judge James Robertson said in a ruling made public today. The ruling is a major victory for the Physicians Committee for Responsible Medicine (PCRM), a Washington, D.C.-based research and advocacy group that had lodged the lawsuit in Federal District Court for the District of Columbia on December 15, 1999

II. Willett's solution: Rebuilding the Food Pyramid:

Exercise forms the base of this pyramid! Hooray! Summary"Whole grain carbs are good, lean animal and vegetable proteins are good, and plant oils are good."

• Healthy carbs - whole grain rice, pasta, and bread plus plant oils should be served at most meals
• Veggies can be eaten in abundance (mmm mmm!), and 2-3 servings of fruit per day (a source of simple carbs, but also fiber and vitamins)
• Nuts - somewhat maligned in the past and relegated to the meat category before - are recommended due to their high protein content and presence of good plant oils, and vitamins (particularly E), and delicious beans and legumes like lentils as a great source of fiber, complex carbs, and vitamins.
• Fish and poultry up to twice a day (great sources of protein, low saturated fats and brain-power promoting omega fatty acids)
• Dairy products or eggs up to twice a day (great sources of calcium and protein, but at the expense of saturated fat consumption)
• Red meat and butter for their bad fats and white refined flours and (snif) the potato are at the peak of this pyramid- use sparingly - !! Eating these carbs causes rapid increases in blood sugar, and have probably contributed significantly to today's obesity epidemic.....

What about today'shottest trends in dieting?

3. The Atkins Diet...20 million people have tried it! Summary: "Carbs are bad, Protein and fats - even saturated fats - are good". The main idea: limit carbs intake so the body must burn fat as fuel. The Atkins induction phase results in a semi-starvaton state known as ketosis. Ketosis results when low levels of carbohydrates force the body to begin burning fat for fuel. Fatty acids are released into the bloodstream and converted to ketones, which are excreted in urine. The low carb publicity frenzy of the last few years has caused major fast food chains and restaurants to offer 'low carb' versions of everything from Rally's hamburgers to Subway sandwiches (ie: no bun or bread). From the Atkins website:

• "Phase 1: (14 days) Induction - Low carb ketogenic phase. High protein, but only 20 grams of carbohydrates each day, primarily from salad and other non-starchy vegetables. Goal: switch from a carbohydrate-burning metabolism to a primarily fat-burning metabolism. Weight loss of 10 lbs or more in this phase
• Phase 2: Ongoing Weight Loss (OWL) Add fiber-rich carbohydrates, increasing to 25 grams daily the first week, 30 grams daily the next week and so on until weight loss stops. Then subtract 5 grams of carbohydrate so that you continue sustained, moderate weight loss. Restrict processed/refined carbohydrates such as high-sugar foods, breads, pasta, cereal and starchy vegetables.
• Phase 3: Pre-Maintenance - Transition to weight maintenance by increasing the daily carbohydrates in 10-gram increments each week so long as very gradual weight loss is maintained.
• Phase 4: Lifetime Maintenance - Controlling carbohydrate intake to ensure weight maintenance - this lifestyle is the foundation for a lifetime of better health."

A nutrient analysis of an Atkins sample diet In induction, OWL, and maintenance. WOW!

But, of course, the bad news: Atkins diet alert: December 2003: "A Harvard study published earlier this year in Annals of Internal Medicine showed that show that meat-heavy, high-protein eating patterns are, over the long run, linked to osteoporosis, heart disease, colon cancer, and renal disease, and pose particular dangers for people with diabetes. Ketosis can cause electrolyte depletions leading to life-threatening cardiac arrhythmias ." "Far from vindicating the Atkins diet, the studies published recently in New England Journal of Medicine reinforce what many health professionals have been saying all along: high-protein diets are hard to stick with and the weight loss is unimpressive." See more in the link just above, or see

• "Updated Analysis of Health Problems Associated with High-Protein, High-Fat, Carbohydrate-Restricted Diets Reported via an Online Registry" Physicians Committee for Responsible Medicine, December 2003:
• Doctors Reveal Dangers of Atkins Diet July 15 2003: See their scary ad
• Misunderstandings and Deceptive Statements about Atkins? You decide!

4. South Beach Diet: a newcomer that is taking over Atkins in popularity ! Summary"Some carbs are good, some proteins are good, and some fats are good"! Similar low-carb idea as Atkins, but not as strict. Similar eating 'pyramid' to Willett's recommendations, but with the initial low carb 'induction' to kick start that weight loss. South Beach relies on the glycemic index (how rapidly blood glucose and insulin levels rise after eating a carbohydrate) to determine good carbs from bad carbs (ie potatoes vs whole grains). Under South Beach, bad carbs with a high glycemic index (like refined flour products, potatoes, pasta, and white rice) are forbidden, while good carbs with a low glycemic index (like whole wheat products and wild rice) are OK. From the South Beach website:

• "Phase 1 (14days) : Extremely low-carb, ketogenic phase: "normal-size helpings of meat, chicken, turkey, fish, and shellfish, vegetables, eggs, cheese, nuts and olive oil and even dessert. But - NO bread, rice, potatoes, pasta, or baked goods. No fruit, candy, cake, cookies, ice cream, or sugar, beer or alcohol. Up to10-13 pounds lost.
• Phase 2: Reintroduce carbs - pick and choose which to add back....only some, and in small portions. "Whole grain bread, pasta, rice or cereal, plus fruit and chocolate." Potatoes, fruits and veggies with a 'high glycemic index' are avoided, as are fried foods, saturated fats, sausages.
• Phase 3: "The stage that lasts the rest of your life.... Eating normal foods in normal-size portions- forget all about the South Beach Diet.
• Like Atkins, relies on 'lifestyle changes' to carry a person through, but don't require a product line of Low Carb products made especially for the diet."

Weird Al's Grapefruit diet (oh yea...) Just kidding :)

V. Summary: Whatever way you find works best for you to Eat Well in 2004, remember that: “A fad-free approach to long-term weight loss is best, and that means a diet rich in fruits, vegetables, whole grains, beans, and rice,” says Jen Keller, R.D., staff dietitian for PCRM...

Carbohydrates are needed as a ready supply of fuel for cellular respiration. "Best" carbohydrates for steady blood sugar, cardiovascular health and intestinal health: Complex carbs, whole wheat bread, brown rice, and whole wheat pasta..

Proteins are needed to build, maintain, and repair muscles, organs, tissues. "Best" proteins for cardiovascular health are lean animal and vegetable protein, fish, eggs, low or non-fat dairy products.

Fats are needed for proper functioning of nerves and brain cells, allow absorption of the fat-soluble vitamins A,D,E and K, provide needed fatty acids and cholesterol for cell membranes. "Best" fats are mono- or poly-unsaturated vegetable oils (olive oil, canola oil); limit saturated fats in red meat, butter, cheese, avoid partially hydrogenated oils with trans fats. Except oreos...:)

One more thing there is no debate about...get in that physical activity! However and whatever you eat, to lose weight, you need to burn more calories than you take in. For cardiovascular health, blood sugar and weight control, and personal well-being, physical exercise can be the key. For most of us, that means "Get movin" ! *(Have some fun outdoors! Try 10,000 Steps ! The McDonalds Go Active happy meal for adults - being test-run in Indianapolis! Whatever it takes!)*

A final disclaimer: It is VERY important to see your family physician before starting any diet plan, particularly a low carb plan, to make sure that your kidneys are healthy and your blood sugar levels are in the normal range.

• Some facts about overweight and obesity in the US Wow...65% of adults in the US!
• Ouch - this one is painful to read!: The New York Times Book Review, by Michael Pollen, Sunday January 12, 2003. SuperSizing America, by Greg Critser. The nutritional implications of the fast-food business model....(Want to increase profits? Get people to EAT MORE...a LOT more!)
• 2/6/04: NY Times Supersizing America continued...Study Details 30-Year Increase in Calorie Consumption: "From 1971 to 2000, the study found, women increased their caloric intake by 22 percent, men by 7 percent. Much of the change was found to be due to an increase in the amount of carbohydrates we have been eating...." Good article!

Objectives:

1. Compare and contrast the USDA Food Pyramid with Dr. Willett's pyramid in terms of recommendations about carbohydrates, fats, and proteins.
2. What is ketosis and how does it relate to the Atkins and South Beach diets?
3. Compare and contrast the Atkins diet and the South Beach diet.
4. What does 'glycemic index' describe and how is it related to carbohydrates?
5. Describe some of the health problems associated with low carb diets.