Category Archives: nutrition

Nutrition of cruciferous Vegetables – Kale

Kale is a leafy green vegetable belonging to the Brassica family, a group of vegetables that includes cabbage, collard greens, and Brussels sprouts.  Half a cup of chopped, boiled kale has only 18 calories, 30% of the daily requirement (RDA) of Vitamin C, and enough Vitamin A and Vitamin K for the whole day.  Vitamin A is required for the formation of rhodopsin, a photoreceptor pigment in the retina.  Vitamin K controls the formation of coagulation factors in the liver.

The sulfur-containing phytonutrients in cabbage, broccoli and other cruciferous vegetables have been shown to reduce the occurrence of a wide variety of cancers.  It is thought that the sulfurous compounds activate detoxifing enzymes in the liver that help neutralize substances that are potentially carcinogenic.

A study found that people who ate the most cruciferous vegetables had a 29% lower risk of bladder cancer than those eating the least of this family of vegetables.[1]  Another study found reduced intestinal polyps when the diet contained sulforaphane.[2]  Sulforaphane is an isothiocyanate that is present abundantly in broccoli and cauliflower.

Kale, broccoli, and cabbage should be in your menu if you are trying to lose weight while maintaining good nutrition.

Learn more about vitamins

[1] Zhao H, Lin J, Grossman HB, Hernandez LM, Dinney CP, Wu X. Dietary isothiocyanates, GSTM1, GSTT1, NAT2 polymorphisms and bladder cancer risk. Int J Cancer. 2007 May 15;120(10):2208-13. 2007. PMID:17290402.

[2] Hu R, Khor TO, Shen G, Jeong WS, Hebbar V, Chen C, Xu C, Reddy B, Chada K, Kong AN. Cancer chemoprevention of intestinal polyposis in ApcMin/+ mice by sulforaphane, a natural product derived from cruciferous vegetable. Carcinogenesis. 2006 May 4; 2006. PMID:16675473.

What is the difference between diets?

Before and After

As the waistlines of Americans expand, so do the number of diet books in library shelves.  There is such a huge number of diet books, that it is impossible to figure out which one is the best.  Every doctor who writes a book claims to have a superior diet, and all doctors criticize each other’s diets.  The average person is completely confused because they don’t know whom to trust.  The problem is compounded because anybody, even celebrities who know nothing of nutrition, can write diet books.

The purpose of a diet is to provide guidelines for healthful eating, but most diet books also give advice about how to lose excess weight.  A basic diet is supposed to provide adequate amounts of protein, essential fatty acids, vitamins, and trace minerals.  The total number of calories can then be regulated to allow weight loss or to maintain weight.  The differences in the diets like Atkins, South Beach, Ornish, and others, depends on the proportions and sources of proteins and fats.  The Atkins diet allows a variety of meats, whereas the Ornish diet is mostly vegetarian.  The big differences in the diets seem to be:

How much exercise should you get? Some diets emphasize exercise as a way of burning extra calories and firming up muscles.

How much protein should you eat? Protein provides satiety and makes you less hungry.  High protein diets like the Protein Power Plan or the Zone Diet say that approximately 30% of the calories should come from protein sources such as meats, poultry, fish, and dairy.

What percent of your diet should be fat? The range can be anywhere from 15% to 50%.  The Ornish diet tends toward the lower end of the range.  The types of fats are also important.  Fats are structural components of the body.  The brain, for example, consists of 60% fat.  Hydrogenated fats and trans fats are harmful for the heart and the brain.  Polyunsturated fats, like those in walnuts, reduce cholesterol levels, whereas saturated fats from animal fats and tropical oils like coconut and palm kernel, increase cholesterol levels.

How many calories should you eat? This depends on whether you want to lose weight or maintain weight for a specific level of activity.  Sedentary people need fewer calories than people who exercise.  One hour of vigorous exercise burns approximately 400 calories.

What proportion of carbohydrates should you eat? This usually is decided by the amount of protein and fat in the diet.  The real question is what type of carbohydrates should be consumed.  Starchy carbohydrates don’t have enough vitamins and nutrients to meet normal requirements, and excess starch is stored as fat in the body.  Leafy green and non-starchy vegetables are nutritionally superior.

How do you spread your calorie intake over time?
Some diets say that it better to eat five small meals throughout the day to minimize insulin spikes.  Other diets advocate taking most of the calories in one main meal to get the body into a ketogenic, fat-burning mode during the fasting period.

The success of a diet to lose weight depends on being able to maintain a lower calorie intake without being deprived.  This is easier to achieve with high-protein, low-carbohydrate diets.

Learn more about weight control and diets

Foraging for mushrooms and bamboo shoots

Bamboo Shoots Bamboo Shoot cross section
Bamboo Shoots

After almost one week of continuous spring rains, the trees are green and the the ground is moist.  These conditions promote the growth of mushrooms and bamboo.  A nice walk in the woods will bring you closer to nature, burn up some calories and, if you are lucky, you can find some edible mushrooms, berries, or bamboo shoots.

Bamboo shoots are frequently used in Chinese cooking.  They are also a favorite food of Panda Bears.  Bamboo shoots are low in calories and contain a significant amount of B vitamins and minerals.  100 grams of raw bamboo shoots have only 27 calories and the following nutrients:

Nutrients in Bamboo Shoots

Next time that you go for a walk, keep your eyes open.  You can enjoy nature, and perhaps find a nice edible treat.

How we get fat: Buy one, get one free

Free Bacon, Free Sausage  Buy one, get one free (BOGO)
Buy one, get one free

According to the World Health Organization (WHO) there are now over 1.6 billion overweight adults in the world. That number is projected to grow by 40% over the next 10 years. The following list reflects the percentage of overweight adults aged 15 and over. These are individuals who have Body Mass Index greater than or equal to 25. Obesity is defined as a BMI greater than or equal to 30.  In the United States 74.1% of the people are overweight or obese.  That is almost 3/4 of the entire population.

Rank Country %
1. Nauru 94.5
2. Micronesia 91.1
3. Cook Islands 90.9
4. Tonga 90.8
5. Niue 81.7
6. Samoa 80.4
7. Palau 78.4
8. Kuwait 74.2
9. United States 74.1
10. Kiribati 73.6
11. Dominica 71.0
12. Barbados 69.7
13. Argentina 69.4
14. Egypt 69.4
15. Malta 68.7
16. Greece 68.5
17. New Zealand 68.4
18. United Arab Emirates 68.3
19. Mexico 68.1
20. Trinidad and Tobago 67.9

One of the reasons why Americans are so fat is that they cannot pass up a bargain.  The way in which food is merchandised makes it virtually impossible to buy only a reasonable amount of food.  Look at the receipt above.  You buy one and you get one free.  If you buy only one, it is like throwing half of your money away.  Who is going to do that?  Nobody.  We would rather eat it than waste it.  That is how we get fat.  Interestingly, you seldom see such sales for fruits and vegetables.

Vegetarian Gorillas

Gorilla profile

Have you ever looked at the stomach of a gorilla? Their abdomen is almost twice the circumference of their chest.  They are definitely pot-bellied.  One of the evolutionary differences between humans and other great apes was the reduction of the length of the intestinal tract. This was achieved through bipedalism and tool use.  By hunting and fishing, humans could get nutrient-dense meats and fish instead of being limited to fibrous, hard-to-digest vegetables.

The introduction of fire for cooking 300,000 years ago also influenced the reduction of the length of the human digestive tract.  Cooked foods are softer and more digestible than raw foods, and cooking improves longevity by killing pathogenic bacteria and parasites that can cause diseases.  The Neanderthals that preceded us had a bulky mid-section that was advantageous because it kept them warmer during the cold weather of the ice ages.  The use of fire by hominids for heating and for cooking was well established by the time that modern humans appeared 160,000 years ago.

If we were limited to eating raw fruits and green vegetables, we would need to eat a lot.  To get about 2000 calories, it would be necessary to eat 3 apples, 2 oranges, one whole head of lettuce, 4 medium carrots, 5 figs, 4 large tomatoes, 4 bananas, and 1 cup of walnuts.  The walnuts contain about one third of the total calories, but all this food only has 39 grams of protein which is about two thirds of what an average human needs.  Modern vegetarian diets reduce the amount of food needed by using beans and grains that must be cooked, but are more nutrient-dense than fruits and vegetables that have a lot of water.  The inclusion of eggs, milk, meats, and fish further reduce the quantity of food needed in the diet. Some vitamins, such as Vitamin B12, are found primarily in meat, eggs and dairy products.  The proper balance of animal products, vegetables, and fruits provides the complete nutrition required for modern humans.

Oprah Winfrey’s diet failure

Oprah Winfrey 1988 Oprah Winfrey 2008
Oprah Winfrey in 1988 and 2008

Oprah Winfrey has a history of yo-yo dieting that has been parodied on Saturday Night Live.  In 1988 she lost 67 pounds on a liquid protein diet and appeared on her talk show dressed in size 10 Calvin Klein blue jeans wheeling a wagon loaded with fat representing the weight that she had lost.  Recalling the occasion in 2005, she said:

“I had literally starved myself for four months – not a morsel of food. Two hours after that show, I started eating to celebrate. Of course, within two days those jeans no longer fit!”

The talk show hostess now weighs 200 pounds, up from 160 in 2006, according to an article in the January 2009 issue of O magazine.  Oprah writes:

“I’m mad at myself.  I’m embarrassed. I can’t believe that after all these years, all the things I know how to do, I’m still talking about my weight. I look at my thinner self and think, ‘How did I let this happen again?’ “

Oprah has blamed her weight problems on an out-of-balance thyroid and her fear of working out because of her condition.  In 1990, she regained the 67 pounds that she had lost saying:

“I’ve been dieting since 1977.  The reason I failed is that diets don’t work. I tell people, if you’re underweight, go on a diet and you’ll gain everything you lost plus more. Now I’m trying to find a way to live in a world with food without being controlled by it, without being a compulsive eater. That’s why I say I will never diet again.”

In 1994, she had slimmed down by exercising with the help of a personal trainer and a full-time, in-house chef. She even finished the Marine Corps Marathon. Oprah kept up the fitness regime through 1996, when she posed on the cover of People magazine, in which she described the diet and workout routine that finally worked for her.  In 2007, Oprah told viewers that a thyroid disorder had caused her to gain 20 pounds.  Oprah feels embarrassed by her current weight of 200 pounds.

The lesson that we can take from Winfrey’s experience is that proper nutrition and exercise have to be a way of life.  You cannot just say “I am going to lose weight” and stop eating or go on a fad diet.  You have to figure out how to meet your nutritional needs for your target weight by eating real foods.  You also have to be realistic about your goals.  You should not wish to be too thin or too muscular.  You have to aim for a normal weight and be happy with that.  You also have to limit your consumption, even if you can afford abundance.  And you have to be consistent.  You have to set your goals and remain steadfast. This requires psychological strength.

Don’t be afraid of Sugar

Teaspoon of Sugar
A teaspoon of sugar has 15 Calories

Many people try to lose weight by cutting down on the amount of sweets that they eat.  This is a good idea, but it will not be effective unless the total calories in the diet are reduced.

A study compared two diets containing 1100 Calories.[1]   The diets had the same percentages of fat (11%), protein (19%) and carbohydrate (71%).  The only difference was where the carbohydrates came from. In one group, 43% of the calories came from white sugar (about 118 grams or 30 teaspoons). In the other diet, only 4% came from white sugar (about 11 grams or 3 teaspoons), and the rest was derived from starches and complex carbohydrates.  Both groups experienced the same decreases in weight, blood pressure, percentage body fat, and the same changes in total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.  The fasting blood sugar was reduced to the same extent in both groups.  Each group lost about 7 kilograms (almost 15 pounds) over the 6 weeks of the study.  The authors concluded that:

“the use of sucrose in a weight-loss regimen is unlikely to cause problems for the average patient, as long as total energy intake is restricted.”

Although white sugar will not make you fat, it is a highly refined carbohydrate that does not have any other nutrients.  If you want something sweet, it is better to eat oranges, pears, grapes, dates, raisins, and other fruits which have fiber and natural vitamins and minerals.  If you want to lose weight, you have to reduce the total calories in your diet, but you don’t have to be afraid of sugar in small quantities.

[1] Surwit RS, et al., Metabolic and behavioral effects of a high-sucrose diet during weight loss, Am J Clin Nutr. 1997 Apr; 65(4):908-15. PMID: 9094871

Overeating during the holidays and weight loss scams

Weight loss fake pictures

Are you feeling fat after eating so much over the Thanksgiving holiday?  If so, you may be tempted to try some of the impressive weight loss diets advertised on the internet.

The advertisement above shows some pictures of a woman’s remarkable transformation after losing 44 pounds.  In your eagerness to click on the advertisement, you may overlook the fact that the picture is a fake.   Here are some ways to tell that the claims are fake:

1) The advertisement claims a 44 pound loss.  For every loss of weight of 6 or 7 pounds there is a waist size reduction of about 1 inch.  A person could only lose about 6 or 7 inches at the waist by losing 44 pounds.  With the pants folded in half, the slack would be only three or four inches.  But look at the picture.  There are about 6 inches of slack or about 12 inches in circumference.  That would correspond to a weight loss of around 80 pounds.

2) Notice the width of the pant legs in both pictures.  The legs of the pants on the right are much wider than the legs of the pants on the left.  Do you seriously think that the model in the picture would be able to put her hips and both legs into one pant leg?  Since the face is not shown, we have to ask: is it the same girl in both pictures?

Avoid weight loss scams.  The only way that you can lose weight is by avoiding junk food and cutting calories.

Effect of SIRT1 genes on neurodegenerative diseases and cancer

Dr. Leonard Guarente
Dr. Leonard Guarente

Today, I attended a lecture at the National Institutes of Health by Dr. Leonard Guarente of MIT.  Dr. Guarente has dedicated his career to the study of the molecular mechanisms that affect life span and the development of the diseases associated with aging.  One of his particular interests is the study of mammalian SIRT genes that are involved in changes in stress resistance and metabolism known to be associated with Calorie Restriction (CR). The CR diet not only extends life span in rodents, but also protects against many diseases of aging, including diabetes, cardiovascular disease, neurodegenerative disease, cancer and osteoporosis.

Dr. Guarente described recent findings in his laboratory regarding SIRT1 function in specific mammalian tissues and in specific disease models.  Dr. Guarente’s lab has recently shown that genetic interventions that enhance the activity of the mammalian sirtuin SIRT1 can mitigate major diseases of aging in mice, such as neurodegenerative diseases and cancer.  Increased expression of the SIRT1 gene in experimental animals was able to decrease cancer, decrease the formation of beta amyloid plaque in the brain, and decrease osteoporosis, but overexpression of the gene was fatal.  It seems that there is an optimum amount of gene expression which promotes health, and that too much is actually worse.

Dr. Guarente posed with me for this photograph.  When I told him that I was a member of the Calorie Restriction Society, he said: “You don’t look too thin.”  I answered that I was not an extreme dieter, and that I only restricted about 10 percent.

Antonio Zamora and Dr. Leonard Guarente

Watered down milk in the dairy section

watered down milk  watered down milk ingredients

Last weekend I visited a friend who had unwittingly bought a carton of what he thought was 2% Reduced Fat Milk.  When I poured some of the product on my cereal, I noticed that the liquid did not have the smooth texture of milk.  It appeared to have small lumps like milk that is starting to curdle from spoilage.  Since he had just bought it, I looked at the label more closely.  It was not milk.  It was a “dairy beverage”.

The first ingredient in the Ingredient List of the label was water, followed by ultrafiltered fat free milk, cream, inorganic calcium and phosphorus salts, and emulsifiers (mono- and diglycerides), thickeners (carrageenan, locust bean gum), and artificial sweeteners (sucralose and acesulfame potassium).  Food labels are required to list the ingredients in decreasing order of concentration.  Since water is listed before the fat free milk, this means that the product contains more water than milk.

What scared me about this product was that the label said that a one-cup serving had 8 grams of protein — the same as skim milk.  If the product is half water and half skim milk, I would expect it to have half the protein.  Where is the extra protein coming from?  The ingredient list did not say.  This made me think about the recent scandal in China where watered down milk was adulterated with melamine to fool the standard tests for protein.

The discrepancy between the ingredient list and the nutrition facts indicates that something is wrong with this product.  Unfortunately, the FDA does not have enough resources to track down all labeling violations.