Thursday, March 29, 2012

Pork aplenty!

Pork tenderloin is a great source of lean protein, and it's so easy to cook!

I got a gallon Ziploc bag, put about 3 pounds of pork tenderloin in it, and poured in a bottle of oil & vinegar - based salad dressing. I marinated it in the fridge for 22 hours, then 2 hours before I was ready to cook it, I let it sit out on the counter to get to room temperature. 

After I preheated the oven to 475°, I dumped the contents out into a baking pan and arranged the tenderloins comfortably.
I let them roast for 15 minutes at 475°, then turned the oven down to 425° for another 30 minutes. At that point, I started taking the tenderloins out of the oven to check the temperature of the meat. When it registered 155° or so, I knew it was finished cooking since I like medium - medium well pork. The total oven time can be anywhere from 45 - 60 minutes.
Here it is at the dinner table, served with its own juices poured all over, with a nice escarole salad on the side. Enjoy!

Wednesday, March 21, 2012

All calories are not created equal

How do different calorie sources (carbs, protein, fat) affect our bodies? 
First, here's a great resource to be "Snack Neutral." Plug in your snack, plug in your activity level, and see if you can cancel out your calories. 

Let’s say a 140 pound person needs 1900 calories a day to maintain his weight.
  •  All 1900 calories come from carbohydrates, this person would become overweight, still feel hungry, and would be deconstructing his own muscle fibers to avail protein for vital processes.
  • All 1900 calories come from protein, this person will likely lose weight with serious kidney and liver problems.  
  • All 1900 calories come from fat, this person will likely become overweight with serious heart problems.
Did you know obesity is a problem not because of over-nourishment, but rather under-nourishment? Why? Carbohydrates are the least costly kind of food, followed by oils, with protein-rich foods trailing far behind. This is because of the scarcity of nitrogen (in protein), vitamins, and minerals relative to the abundance of carbon (in carbohydrates and fat) in food. Obesity, with its strongest ally being poverty, is prevalent among those who are under-nourished in protein and fruits and vegetables. The chief concern among the poor is first, “Did you eat?” not, “Did you get enough fruits, vegetables, and protein?” The cheapest and easiest way for a poor person to eat is by consuming excess carbohydrates, usually processed with fat (i.e., chips, fries, donuts…). Again, if protein is missing from the diet, the body’s muscle tends to shrink away while fat reserves pile on. Muscle requires more energy to maintain than fat reserves do, so the person’s caloric requirements lessen. If caloric intake stays the same while requirements become lower, the fat accumulates even faster. Thus, obesity sets in.
How do carbohydrates, proteins, and fats affect the body?
·         Some destinations for carbohydrates:
1.       Energy and Carbon Dioxide
2.       Fat production
3.       Nucleotides in DNA and RNA
4.       Hunger Signaling:
a.      Ghrelin is a hormone that the empty stomach secretes, signaling “Hungry!” Carbs quickly suppress ghrelin at first, but within  2-3 hours, ghrelin rises to a level that’s higher than normal, saying, “HUNGRY!” 
b.      Insulin, a hormone produced by the pancreas, is secreted when blood sugar is high. People with Type 2 Diabetes are resistant to insulin. Insulin increases the excretion of leptin, thereby indirectly signaling “Full!” Insulin tells the body to begin making fat out of the excess sugar.
c.       Leptin, a hormone secreted by fat cells, signals “Full!” This helps us maintain a stable weight. However, obese people are often resistant to leptin, ignoring its signals to stop eating. Emotional stress can increase leptin, so that people who are stressed out tend to eat less. 
·         Some destinations for proteins:
1.       Energy, Carbon Dioxide, Ammonia or Uric Acid
2.       Enzymes that catalyze most bodily processes
3.       Formation of antibodies for immunity
4.       Gateways in cell walls for the passage of nutrients
5.       Mucous production
6.       Cell structure and shape
7.       Muscles, hair, finger and toenails
8.       Hunger Signaling: Proteins don’t suppress ghrelin quickly but rather do so gradually, keeping you fuller longer.
·         Some destinations for fats:
1.       Energy + Carbon Dioxide
2.       Fat accumulation
3.       Neural tissue
4.       Cholesterol production
5.       Hormone production
6.       Cell wall maintenance and water retention
To maintain a healthy weight, there appears to be a need for some sort of balance between the three types of calorie sources, right? Let’s look at a few diet options:
1.       LOW CARB DIETS: Carbohydrates (sugars) are scarce within the body for energy, so protein and fat (both from the diet and from body tissues) are broken down and their hydrocarbons are used for energy (natural gas and petroleum are other examples of hydrocarbons that provide energy). However, since protein and fat are not carbohydrates, they’re made up of more than just hydrocarbons, and the leftover byproducts form ketone bodies which are further metabolized into uric acid (the main component of urine). High levels of uric acid are dangerous to those who have livers and/or kidneys that don’t function well, causing further damage to these sensitive organs that purge our bodies of toxins. The American Dietetic Association’s position on this is clear. Avoid diets that allow unrestricted protein and fat while restricting carbohydrates. These tend to increase cholesterol especially if the fats consumed are saturated (and, to some extent, if there also is high cholesterol content).
2.       ATHLETIC DIETS: Carbohydrates are the most efficient fuel for the body, since we humans are well equipped with fast-acting enzymes that break down the sugar chains in starches. We also have high-capacity intestinal absorption of the resulting free sugars (Ruminants like cattle absorb and metabolize proteins more efficiently than starches and sugars, since their true stomach receives post-fermentative products from the rumen, i.e., low carbohydrate, high protein material). Muscles and the brain primarily operate on energy from carbohydrates. Getting enough carbohydrates in the diet is important so that your body won’t have to break down its own muscles to provide itself with energy…sounds counter-productive to your workout goals, right?
  • ·         How many carbohydrates do you need if you’re doing normal daily exercise? Multiply your weight by 2.3 for light exercise (30 min. walking, light weights, casual sports) or 3.2 for more moderate exercise (running, moderate weight-lifting, daily sports). A 140 lb person doing light exercise needs 322 grams of carbohydrates a day (1288 calories from carbs).
  • ·         How much protein do you need? Multiply your weight by 0.55 (light exercise) or 0.8 (moderate). A 140 lb person that does light daily exercise needs 77 grams of protein a day (308 calories).
  • ·         What about fat? Well, the ADA makes no quantifiable requirement for fat, other than asserting that it’s essential. A 140 lb person needs to eat about 1900 calories to maintain their weight, so that leaves about 300 calories for fat, which is necessary for appetite suppression and satiety, water retention, cell health (all membranes of cells and organelles are fat-based), and for delivering fat soluble vitamins such as A, D, E, and K. The best fats are from oils found in fish, nuts, avocados, olives, flax, and greasy (not grizzly!) beef. A gram of fat has 9 calories, so about 33 grams of fat would fit well into this diet.

3.       SEDENTARY DIETS: For those who do not have time to exercise, do not like to exercise, or are unable to exercise, the best choice is to modify the Athletic Diet and reduce the carbohydrate portion. By eliminating 200 calories worth of carbohydrates, a 140 lb sedentary person can maintain a healthy weight with about 1700 calories. This person isn’t burning off 200 calories a day in exercise that the 1900 calorie moderate exerciser is. We all need to consume about 10 calories per pound of body weight just to keep our heart pumping and everything functioning at that weight (supplying basal metabolism for 140 lb person = consuming 1400 calories of energy). A little more energy is required to process the food we eat (the more food eaten, the more energy required to process it), and more energy on top of that is required for any voluntary activity like writing, sitting up straight, and walking. I echo what the American Dietetics Association says in not so many words: eating more calories and working out is a lot more fun and brings about results faster than restricting calories and sitting still!

Overall, for the moderately active individual, about 2/3 of the calories in the diet are to come from carbohydrates, 1/6 from protein, and 1/6 is to come from fat.

Carbs make up quite a bit of this diet, right? Remember that fruits (and vegetables, but less so) are also sources of carbohydrates besides cereals and starches. They contain plenty of water and fiber to keep you satisfied while taking advantage of all the vitamins, minerals, and antioxidants they contain.

Now what to do for your healthy weight goals? Well, don't use a scale to guide your weight goals. How do you know if 140 pounds are mostly lean muscle or flab? Don't obsess over numbers. Caloric intakes of 1700 or 1900 are just loose guides; as the unique individual you are, you probably do not fit the average recommendation! Pay attention to the way your clothes fit and the way your body looks in the mirror in response to your diet and exercise routine, then make your own adjustments according to what you Think about calories from carbohydrates, proteins, and fat.

 (Unless otherwise cited, I've taken much of this information from Fundamentals of Biochemistry: Life at the Molecular level (3rd Edition) by Voet, Voet, & Pratt (2008))

Tuesday, March 13, 2012

Food Prices and World Hunger

The following is a summary from “Escalating Food Prices”, a UNICEF publication by Ortiz et al., 2011:

Worldwide food (dairy, meat, sugar, and oilseeds) and cereal prices have each increased 75% since 2007. The 2007-2008 food crisis (remember when gas and corn got so expensive?) was partly caused by weather issues (Drought in Eurasia and South America, Flooding in Central and North America) that produced crop shortfalls. Other than that, it was pretty politically driven by energy matters.
Government policy can directly impact food economics worldwide. For example, Russia in 2010 announced its ban on grain exports, and European wheat futures flew up 12% within that one day.
The relationship between financial speculation pressure and food prices was also observed. Buying commodity futures is supposed to be about “hedging” risk, but rather it has turned into an investment game just like any other non-food commodity or stock. Two percent of the time, contracts end on the commodity delivery date. The remaining 98 percent are traded before they expire so that speculative gains may be won. This kind of activity adds to volatility in food commodity markets, which can threaten the lives of people around the world who await the physical commodities as food.
Additionally, what might be a slight price increase in richer countries consistently has poorer countries feeling a sharply increasing price. Low-income countries paid an average of 8.3% more for food than higher-income countries. Higher food costs in poor households increases debt, malnutrition, child labor, mothers and fathers’ work hours. It decreases meals eaten and medical attention sought.
From 1970 to 2010, the number of hungry persons has increased from slightly less than 900 million to just over 900 million. The proportion of the world’s population that this represents has decreased from just under 40% to around 16%, going from about 1 in 3 people hungry to about 1 in 6 people hungry worldwide. However, it should be noted that in the food crisis of 2008, that number of hungry people spiked to over 1 billion (20%, or 1 in 5 people hungry worldwide). Rising prices in food can generate more poverty, economic inequality, and inflation.
According to Nobel Peace Prize winner Amartya Sen who research worldwide hunger, the main obstacle for feeding everyone is food’s distribution and access. A greater need for transportation and storage infrastructure as well as for domestic agriculture exists in hungry countries. More attention has been brought to the matter of excessive commodity speculation and many governments have pledged to increase supervision of these activities.
Governments can respond to or prepare for food crises by:
Managing Consumption:
Food assistance, price subsidies, price controls, cash transfers, lower taxes, food-for-work
Managing Production:
Creating production subsidies, lowering taxes
Managing Commodity Markets:
Lowering import tariffs, building up food stocks, banning imports, raising tariffs, banning exports, price support

For the poor across the world, from the U.S.A. to the Sudan, increases in food price can stomp out someone’s dreams, unravel the family structure, disempower, sicken and even kill. You may hear over and over that the U.S. average is 10% of the income is spent on food (USDA 2008 Percent ofIncome Spent on Food). We are so blessed to have up to 90% of the rest of our income to spend as we please. Some of our “Media Foodies” disagree with this, saying we need to be spending a greater portion of our income on food, but they never suggest what is to be eliminated from our expenditures to make this replacement possible. Even when local, fresh food is available, fabulous, and nationally famous, the neighbors just might not come and buy it if it’s too expensive. Remember the book Animal, Vegetable, Miracle? Their farm store isn’t doing too well financially. Pressing the local food movement on people just won't work if it doesn't work in their budget.

We rarely hear that currently, low-income (< $20,000/y) Americans spend 19 - 25% of their income on food. Americans spent about 25% (on average) of their income on food in 1930. Still, middle income countries spend 25-40% per capita on food, while low income countries spend from 40 – 47% (US Census Data, 2012). Again, how blessed we’ve been with equipment improvements and mechanizations, hybrid seeds and advanced breeding techniques, fertilizer and safe pesticides, that even at our “poorest” this last century, we were still eating like middle-income countries! 

What do you Think?

Monday, March 12, 2012

"Pink Slime": Neat or Nasty?

Lean finely textured beef (LFTB, or "pink slime") has appeared on ABC News, having run several news segments last week on the topic.