Sweet Potato

Although related, sweet potatoes are NOT, in fact, potatoes. Believe it or not, they are members of the morning glory family. Yams, on the other hand, are tubers – aka potatoes. These two vegetables, which are often confused, even in produce departments, are very different in appearance, flavor and nutrients.

Sweet potatoes are typically long with tapered ends and pale brown to almost purple skin. The flesh is usually orange, although there are some lighter colored varieties. Yams have rough, bark-like skin and a round or oblong shape. The flesh is similar to a russet potato.

Yams are much more akin to a traditional potato and are used for boiling, roasting and grilling; while sweet potatoes are sweet and moist and are often used in pies and casseroles. Believe me, you would not confuse a sweet potato pie with a yam pie. Yuck! So the next time you make candied yams – be sure you grab sweet potatoes – unless you don’t like the people to whom you will be serving it.

Nutrient Profile for a Sweet Potato
90 calories
Fat 0 grams
Protein 2 grams
Vitamin C 32%DV
Vitamin A 383%DV
Iron 4%DV

Nutrient Profile for a Yam
79 calories
Fat 0 grams
Protein 1 gram
Vitamin C 13%DV
Vitamin A 1.5%DV
Iron 4%DV

Potatoes -go organic as you can't remove chemicals that have been absorbed into the flesh.

Last summer, the Environmental Working Group, a nonprofit that uses the power of public information to protect public health and the environment, released their “Dirty Dozen” report which lists the 12 fruits and vegetables that contain dangerous amounts of pesticides. The EWG reviewed nearly 100,000 produce pesticide reports for the U.S. Department of Agriculture and the U.S. Food and Drug Administration and found that several fruits and vegetables contain 47 to 67 pesticides per serving. These fruits and vegetables are more susceptible to contamination because they have a softer skin which absorbs more pesticides.

According to the EWG you can reduce pesticide exposure by up to 80% by switching to the organic version of the Dirty Dozen. Here is the list of offenders:

1.Celery
2. Peaches
3. Strawberries
4. Apples
5. Domestic blueberries
6. Nectarines
7. Sweet bell peppers
8. Spinach, kale and collard greens
9. Cherries
10. Potatoes
11. Imported grapes
12. Lettuce

There is some good news – there are several conventional (non-organic) fruits and vegetables that are not swimming in pesticides. These fruits and vegetables tend to have a stronger outer layer that provides some protection against pesticide contamination. Here is what the EWG calls the “Clean 15″:

1. Onions
2. Avocados
3. Sweet corn
4. Pineapples
5. Mango
6. Sweet peas
7. Asparagus
8. Kiwi
9. Cabbage
10. Eggplant
11. Cantaloupe
12. Watermelon
13. Grapefruit
14. Sweet potatoes
15. Sweet onions

In addition to the EWG’s Dirty Dozen and Clean 15, Prevention magazine recently featured “7 foods that Should Never Cross Your Lips“. The seven include:

1. Canned tomatoes (the resin linings of tin cans contain bisphenol-A)
2. Cord-fed beef (less nutritious than grass-fed cattle)
3. Microwave popcorn (chemicals in the lining of the bag may cause cancer and infertility)
4. Nonorganic potatoes (root vegetables absorb herbicides, pesticides, and fungicides)
5. Farmed salmon (lower in vitamin D and higher in contaminants, including carcinogens, PCBs, brominated flame retardants, and pesticides)
6. Milk produced with artificial hormones (high levels of the hormone IGF-1 may contribute to breast, prostate, and colon cancers)
7. Conventional apples (don’t develop resistance to pests and are sprayed frequently with pesticides)

As you can see, conventional potatoes and apples make both lists. But don’t despair, in addition to explaining why you should stay away from these toxin-laden foods, Prevention offers a healthy alternative for each one – including budget-friendly tips. For example, check out Wal-Mart’s Great Value label, which does not use rBGH in their milk.

Scientists Continue to Research Obesity Causes

This month’s issue of Nutrition Action, published by the Center for Science in the Public Interest, has a fascinating article on obesity research. The article is an interview with obesity researcher Eric Ravussin, who holds the Douglas L. Gordon Chair in Diabetes and Metabolism at Pennington Biomedical Research Center in Baton Rouge, Louisiana. He also heads Pennington’s Nutrition Obesity Research Center and has a list of additional credentials too long for this posting.

The interview makes it clear that obesity is a complicated issue – for many obese people it’s not just a matter of eating less and moving more. Researchers have determined that there are several factors that come into play including hormones, genetics, and temperature, among others.

Leptin is a Crafty Little Bugger

Leptin, a hormone produced by fat cells, was discovered in 1994 and has been fascinating researchers ever since. Leptin tells the brain when the body has enough fat. Sounds simple enough. But, when a person looses weight and leptin decreases, the body goes into starvation mode and the brain tells the body it needs more food. However, a person’s metabolism adjusts so the person needs fewer calories to stay at the reduced weight. This mixed message often results in the person being constantly hungry and may lead to overeating and regaining the weight. Unfortunately, giving dieters additional leptin does not solve the problem because many overweight people are resistant to leptin, similar to insulin resistance. Scientists and pharmaceutical companies are looking for ways to battle leptin resistance, but so far they have not been successful.

Genetics and Environment Are Intertwined

Genes affect our metabolic rate. People of the same sex, age and body size can have metabolic rates that vary by as much as 500 calories per day. Genes can also affect the amount of activity a person undertakes, separate from exercise. For example, people who fidget (tap their feet, fingers, etc.) burn more calories than people who don’t. When we were hunters and gathers and food was not readily available, we had to eat as much as we could when we had the chance, because the next meal may not be coming for a very long time. These genes have been passed on but our environment has changed so they are no longer relevant. Now we have access to food 24-7 and don’t have to burn hundreds of calories chasing down our next meal. Not a good combination.

Climate Control

One of the contributing factors that I found most interesting is how temperature affects fat. Humans have two types of fat (adipose tissue): brown adipose and white adipose. White adipose tissue is where your body stores calories as fat. Brown adipose tissue actually burns as many calories as muscle. For 20 years scientists believed that brown fat was only present in newborns and disappeared around the age of two. The brown fat helps a newborn maintain its temperature as body heat is generated by the brown fat. But last year studies, surprisingly, found brown fat in adults. The hope is that people may be able to increase their calorie-burning fat. Scientists are currently studying how temperature affects brown fat stores. Before the advent of central heating and air conditioning, people had to burn more calories to stay warm and had their appetites naturally curbed by hot temperatures. Our climate-controlled environments are doing us a disservice in this regard.

Mr. Ravussin speaks to other issues that can affect weight gain including viruses and gut bacteria and also talks about the success of gastric bypass surgery. When asked what we can do to curb the obesity problem, he suggests eating less and eating a lower calorie density diet which allows a person to eat the same volume of food but with fewer calories.

Volumetrics Diet

The Lower Calorie Density approach, often referred to as Volumetrics Eating, was developed by nutritionist Barbara Rolls, PhD. The premise is quite simple (and makes a lot of sense, IMHO):  help people find foods that they can eat lots of while still losing weight. In a nut shell, you want to fill up on low-density foods, like non-starchy vegetables and fruit, that aren’t full of calories. Foods like crackers, cookies, chips and butter are high-density foods which should be kept to a minimum as you get a lot of calories in a very small amount. To find out more about Volumetrics Eating, check out WebMD: http://www.webmd.com/diet/volumetrics-what-it-is.

Fettuccine Alfredo - A High Calorie Density Nightmare

Grilled Fish & Veggies - Low Calorie Density so you can eat more and weigh less

With normal-weight adults now a minority in this country, researchers believe that the obesity epidemic may have peaked with adults, but not with children. We can’t change our genes, but we can change our environment. It’s up to us as individuals, as families and as communities to make a dedicated change to, and be held accountable for, better eating habits and exercise in order to reverse these devastating trends. I would love nothing more than to be greeted one morning with a headline that reads “National Obesity Rate Declines for the First Time in More than a Decade”. How cool would that be!

Don't blame the turkey for making you tired.

Many of us have heard the old wives’ tales about how foods can affect how you feel – both mentally and physically. Things like turkey makes you sleepy (or does it?) and coffee keeps you alert. There was an interesting article in the LA Times yesterday by Marni Jameson that explains the science (or lack thereof) behind how certain foods affect our mood or physical well being. Ms. Jameson interviewed several respected psychologists, psychiatrists and nutritionists to sort the fact from fiction. Here is what the scientists had to say:

1. Sugar Makes Kids Hyperactive – Fiction

While many parents may disagree, researched published in the Journal of the American Medical Association says that sugar does not make kids hyperactive (there are some exceptions, but we are focusing on the majority here). It’s important to look at the factors associated with the sugar intake. Are the kids in an exciting environment like a party with music and games along with cake and ice cream? The behavior is from the stimuli - not the sugar. I have attended plenty of parties where kids have been bouncing off the walls before lunch was served, let alone ice cream and cake or candy. Running around like a crazy person is part of being a kid – don’t hold it against them. Now if only there was a way to get them this excited about cleaning their rooms and doing their homework.

2. Coffee Improves Energy and Mental Performance - Fact

Well, actually it’s the caffeine that’s in the coffee. Caffeine’s benefits include increased focus and attention, not to mention keeping you from falling asleep during the pulse-racing presentation by the accounting department at 3:00 p.m. My apologies to all of the accountants out there—it’s just that reviewing spreadsheets at 3:00 p.m. is nearly impossible without some sort of stimulant (see #8, below).

3. Carbohydrates Make You Feel Calm and Happy - Fiction

There is a false belief held by some nutrition experts that a high-carb snack will improve your mood and help you to feel calm and relaxed because carbs increase serotonin (aka the “happy” hormone). The problem lies in the fact that if you have any protein within a 12-hour time period of having the carb snack, the protein will negate the uptake of the serotonin. So, unless you eat all carbs, all the time, you are not going to realize a benefit. Eating an all carb diet may put you in a good mood, but it may also put you in the hospital.

4. Sugar Takes the Edge Off of Pain – Jury Is Still Out

I have never heard of this before, but am willing to give it a try because if eating a Twix will make my upcoming mammogram more comfortable, I’m all for it. There are conflicting studies regarding this theory, the most recent of which appears in the September issue of Lancet and debunks the theory as myth. Bummer.

5. Chocolate Makes You Happy - Fiction

Say it isn’t so! This is my excuse for eating a piece of Poco Dolce (if you don’t know Poco Dolce, you really must try it—it makes a lovely Christmas gift—hint, hint) on a regular basis. I eat Poco Dolce not because I am unhappy, but rather as a precautionary measure because it’s always a good idea to be prepared. Apparently there is more of the “feel good” chemical phenylethylamine in salami than chocolate. So the next time you feel a little bummed out, reach for the cold cuts instead of the Godiva. 

6. Turkey Makes You Sleepy - Fiction

It’s not the tryptophan in the turkey, it’s trying to digest a high-carb meal of yams, three-bean salad and pumpkin pie that makes you sleepy. Add a glass or two of wine to the equation and it’s lights out. Of course, if you eat at 3:00 p.m. (see #8, below) you may as well eat your Thanksgiving dinner in your PJs.

7. Omega 3 Fatty Acids Help Fight Depression - Fact (with a Caveat)

While there is strong evidence to suggest that this is true for people suffering from clinical depression, there is no evidence that omega 3s (found in fish) can help people who are simply feeling a little blue.

8. What You Eat at Lunch Causes the 3:00 p.m. Slump - Fiction

What makes us tired is simply our innate need as human beings to take a nap around this time. It’s all about circadian rhythms, but that’s a subject for another blog post. IMHO we would all be better off if we took a 20-30 minute siesta each afternoon rather than forcing ourselves to stay awake while doing the head bob in front of the computer screen. I think the quality and quantity of work that would be produced after a little rest would far surpass the below-par work that is produced when feeling tired.

9. Water Fights Fatigue and Depression - Fact

Being dehydrated can lead to fatigue, which can make you cranky. Even low levels of dehydration can put you in a bad mood. So the next time a friend or colleague gently trys to tell you that you seem a bit out of sorts, which is code for “Whose house fell on your sister?”, try a glass of water. It might be just the thing you need to improve your mood.

Boy, I’m thirsty. 

Stress is not the enemy in weight gain.

According to a new study led by Dr. Jane Wardle of the University College London in the UK, stress may have only a small impact on weight.  

The study analyzed 32 long-term (one to seven years, and some projects as long as 38 years), international studies conducted in the 1990s and 2000s. After sorting through the meta data, the researchers identified only a modest association between higher levels of stress and weight gain. They found 69% of the studies uncovered no definitive association between higher stress levels and weight gain while 25% of the studies did link stress to weight gain, and 6% found stress linked to weight loss.   

One particularly interesting find is that men, not woman as popularly believed, were more likely to gain weight from increased stress.  

According to co-researcher Dr. Andrew Steptoe “based on the best current scientific research, stress is not likely to play a major role in increasing body weight or obesity for most people.”  

However, this is not to say that stress eating, or lack of eating due to stress, isn’t  a factor in weight gain/loss. Steptoe remarked “some people may increase their food consumption under stress, while others may stop eating and lose their appetites.”  

While the average affect of stress might be small, individual results vary and there are some people for whom stress could have a strong influence on weight gain.

How to Reduce Stress

So while most of us can’t blame stress for weight gain, there is something we can do to help reduce stress and our wasitlines—exercise.  According the Mayo Clinic, exercise can ease your stress levels by:  

• Pumping up your endorphins, those naturally-occurring feel good chemicals the brain produces
• Reducing tension by focusing on physical movements instead of the staff meeting gone bad
• Improving your mood by reducing the symptoms associated with mild depression and anxiety
• Improving your sleep 

So with exercise, you get a two-fer: less stress and less weight. Before some of you start to rationalize about not having the time to exercise, I leave you with this question from cartoonist Randy Glasbergen, “What fits your busy schedule better, exercising one hour a day or being dead 24 hours a day?“

Reading labels can have a significant impact on health.

As I’ve mentioned several times in this blog, reading and understanding nutrition labels is key to one’s overall health. If you need incentive to pay attention to portion size, nutrients and ingredients – how about the idea that doing so could help you lose weight.

A four-year study of 3,706 middle-aged people by Bidisha Mandal, associate professor at Washington State University’s School of Economic Sciences, recently published in the Journal of Consumer Affairs, concluded that  the greatest weight loss was achieved by those people who read nutrition labels and exercised. An interesting finding was that there was a statistically significant reduction in body mass for people who regularly read labels but did not exercise— even more than people who exercised but did not read labels. 

It’s important to read labels, even for those foods that claim to be “diet”, “light”, “reduced calorie”, etc. as what is advertised on the front of the package may be misleading and not tell the entire story, which can only be found on the nutritional label. Many so called “diet” foods include added salt, sugar or fat. Prevention magazine has a list of 14 diet foods to avoid. The “sneaky salt” list includes fat free cottage cheese with the salt equivalent of 2-1/4 one-ounce bags of potato chips. The “sneaky fat” list features low-fat ice cream with almost double the amount of sugar as regular ice cream.

Label Reading Resources

For more information on how to read a label, check out these web sites that offer a lot of good information:

• Mayo Clinic: Nutrition and Healthy Eating – Nutrition Facts: An Interactive Guide to Food Labels
• WebMD: Health & Cooking – How to Read a Nutrition Label
• FDA: How to Understand and Use the Nutritional Facts Label

Several grocery chains have created their own nutritional rating systems, but many of these are too narrowly focused on a limited set of nutrients and/or lead consumers to choose foods that aren’t truly nutritious, such as children’s cereals full of sugar and very little else. Plus, there is no standardization among the various rating systems so what one grocer rates as healthy is not rated the same way by another grocer. Talk about confusing.

Rather than rely on someone else to tell you what is nutritious, take some time to educate yourself and read labels yourself. Once you get the hang of reading labels, which is simple but does take some practice, it will become a healthy habit that can have some really positive effects on your well being.

Pumpkin Cookies

In a follow up to the last Friday Fun Day post on all things pumpkin, I now bring you ideas for making Halloween treats without the fat and calorie horror.

Earlier this week, the Salt Lake Tribune ran an article by Jim Romanoff that talked about simple substitutions you can make to cookie recipes that really cut the fat and calorie content. Some of you may already be familiar with these tricks, but as I am inarguably a terrible cook (I burn water and lettuce – don’t ask), I found these ideas to be very clever and plan on giving the pumpkin double-ginger cookie recipe a try this weekend (fingers crossed that I don’t set off the smoke alarm).

There are several tricks to help cut the fat and calories:

• Replace up to half the butter, margarine or shortening with healthy oils like canola or olive oil.
• Use fruit purees, such as applesauce or my favorite, canned pumpkin, to replace some of the fat. Using fruit puree works best in soft cookie recipes.
• Use nonfat yogurt or buttermilk to keep baked goods moist without adding fat.

The article also suggests that cake flour works best because of its extra fine consistency and because it only has half the protein of regular flour which means it absorbs fat well and produces cookies that are moist even when lower in fat.

Be sure to check out the pumpkin double-ginger recipe. If the taste is as good as the nutritional facts (54 calories per cookie, 1 g fat, 11 g carbs, 1 g protein and 1 g fiber), it should be a winner.

Pumpkin Soup

Fall is my favorite season. While Southern California doesn’t have the changing leaves (with the exception of a few sycamore trees) like much of the country, we have beautiful weather with mild days and cool nights. The air even smells good. Plus, it’s football season. And, let’s not forget Halloween – only the most wonderful holiday ever where I, oops I mean the kids, get to dress up and eat candy. All without the hassles of preparing a big dinner for relatives you’d rather not see or fighting the crowds at the mall in a fruitless search for a Giga Pet.

One of the other special aspects of Fall is the food – especially pumpkin. Pumpkin is an incredibly versatile vegetable that can be used in everything from soups to souffles. You can even bar-b-que pumpkin, just like grilling squash. Some of my favorties include pumpkin waffles, pumpkin soup, pumpkin ravioli, and pumpkin cheesecake. Let me pause for a moment while I wipe the drool forming in the corner of my mouth. Sorry about that.

Pumpkin is not only delicious, but it is also quite nutritious. It is low in Saturated Fat, and very low in Cholesterol and Sodium. It is also a good source of Vitamin E (Alpha Tocopherol), Thiamin, Niacin, Vitamin B6, Folate, Iron, Magnesium and Phosphorus, and a very good source of Dietary Fiber, Vitamin A, Vitamin C, Riboflavin, Potassium, Copper and Manganese. You can see the complete nutrition profile at: http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2601/2#ixzz11jltp1uc

Both fresh and canned pumpkin can be used in many recipes, not just pie. And with the Great Pumpkin Shortage Crisis of 2009 behind us, there should be plenty of pumpkin to go around this season. Here is a list of pumpkin recipe web sites:

pumpkinrecipes.org
allrecipes.com
Better Homes & Gardens
Pumpkin Nook

I hope you get to try some really great pumpkin recipes this season. Enjoy your weekend.

How to Measure Body Fat Using a Tape Measure

Many of us are familiar with BMI (Body Mass Index) charts which tell us, supposedly, if our body mass is healthy, underweight or overweight.    

According to the Centers for Disease Control and Prevention (CDC), “BMI is a number calculated from a person’s weight and height and is a fairly reliable indicator of body fatness for most people. While BMI does not measure body fat directly, research has shown that BMI correlates to direct measures of body fat, such as underwater weighing and dual energy x-ray absorptiometry (DXA).” BMI is an easy-to-calculate method of screening for weight categories that may lead to health problems. The Internet is rife with BMI calculators. Here is a link to the CDC’s calculator for adults and children/teens: http://www.cdc.gov/healthyweight/assessing/bmi/. 

The chart, below, lists the standard weight status categories associated with BMI ranges for adults:

The problem with relying only on BMI is that it is a very one-dimensional picture of a person’s body composition. For example, there are people who may have a BMI in the Normal range, but are actually fat as determined by body fat testing. Conversely, there are people who are deemed obese or overweight, who, in fact, are very lean with minimal body fat. This is because BMI does not take into account how much body weight is muscle and how much is fat. 

This is why it is important to consider body fat percentage in addition to BMI. Body fat percentage is calculated by dividing fat mass by body weight. This calculation can lead to results that not only don’t match the BMI categories, but in some cases, if not made known to the affected individual, could lead to undiagnosede health problems.  

For example, two women are both 5 feet 4 inches tall with a BMI of 24. But if woman #1 has 42 pounds of body fat and 98 pounds of lean mass, she has 30% body fat. This is what is often refered to as normal weight obesity. If woman #2 has only 28 pounds of body fat and 112 pounds of lean mass, her body fat is only 20%. Same weight + same height does not always equal the same composition of fat to lean mass.   

On the other side of the coin, you have people who are incorrectly labeled as overweight or obese according to a BMI chart, especially athletes. My 16-year old son, who works out regularly as a high school football player, is a prime example. According to a BMI chart, he is Overweight. But after measuring his body fat with calipers (which was not easy to do because the kid has almost no fat on him) he falls into the Athlete range on the Body Fat chart (see below). By the way, is there some reverse genetic engineering process that will allow him to pass this trait to his mother? Just asking.  

Body Fat Categories

While the ultimate way to test body fat is via underwater weighing or x-ray absorption as mentioned above, unless a friend or neighbor has x-ray vision or is an expert with his or her own water tank and highly sensitive equipment, and you don’t mind being stark naked – which is required for the water test, these means of measurement are not practical for the majority of people. However, you can measure your body fat, albeit somewhat less precisely, in the comfort of your own home by simply using a tape measure or body fat calipers (you can purchase basic calipers online for a few dollars – check out amazon.com). Body fat calipers require a bit of practice and unless you are a contortionist, someone to assist you with  measuring certain locations, like your lower back.  

Here’s a link on how to measure body fat using a tape measure: http://www.ehow.com/how_4869405_measure-fat-using-tape-measure.html  

If you want to use body fat calipers, you might want to visit this web site for information on how and where to take measurements: http://linear-software.com/online.html 

For many of us, BMI is a good indicator as to whether or not we are at a healthy weight, underweight or overweight. But, if you are more athletic or simply want a more precise indication of your ratio of lean tissue to fat, I recommend taking a few minutes to take your measurements. The results might prove comforting or might motivate you to make changes to improve your overall health and fitness.