nutrition

Weight Loss Basics Explained

4
1229 days
by in equations, food, nutrition

I covered the nitty gritty of digestion from a biological point of view in yesterday’s post. But say you just want to lose that paunch you’ve developed from too many late-night viewings of Dr. Who (accompanied by salty buttered popcorn). Let’s find out:

Say I’ve got a friend, Rose Tyler. Rose is 5’9”, weighs 180 lbs (slightly overweight), consumes 2000 Calories daily, and exerts herself enough to not gain or lose weight. She wants to lose 10% of her bodyweight for a final (and healthy) weight of 162 lbs. A healthy rate of loss is 1-2 lbs/week, so this could take 9-18 weeks to achieve.

1 pound [2.2kg] of body fat is the same as about 3500 Calories [kcal]. Thus to burn one pound of fat requires an expenditure or deficiency of 3500 Calories. Since we’re shooting for 1-2 lbs weekly, that means:

(3500 Calories/week)*(1 week/7 days) = 500 Calories less (or extra exercise) daily. Double this (1000 Calories) for 2 lbs/week.

Reducing food intake is tricky. Undernourishment is possible—especially when exercising—and also puts you at risk of going into “survival mode”, when your body stores more calories as fat. I’d tell Rose to eat a small snack before and after her work out, which should also last a bit longer to account for the extra calories. Eating before and after is helpful in maintaining muscle mass, and also ensuring enough fuel to burn and recover. Also, eating several smaller meals throughout the day evens out caloric intake and ensures your body always has the energy it needs. There are other ways to do this, but you’ll have to wait for the next post!

Energy, Excretion and Exertion

1
1230 days
by in definitions, equations, fitness, food, nutrition

Yesterday’s post focused on how we can use nutrition labels to gauge what we eat. It briefly mentioned that calories are units of energy – but today I’ll explain what calories actually do.

Just like cars, our bodies need fuel. Cars combine refined oils with oxygen into combustible gases, which expand in the piston cylinders and make the wheels turn. You probably know that energy can neither be created nor destroyed. It can only be stored or transferred. So what is actually happens to the energy we obtain from food?

After being broken down in our stomachs, our intestines absorb food nutrients into the blood. As blood is pumped through our bodies, so too are the nutrients which are taken into our cells. Here, glucose is converted into ATP (Adenosine triphosphate) through a series of processes referred to as cellular respiration. The ATP is further broken down into usable biochemical energy, thereby creating water, carbon dioxide and heat as byproducts.

This video brings back memories of high school freshman biology, but it’s detailed, short and not too complex:

So then what? Of the usable energy,

  • 65-75% goes to fueling our bodies core needs. The speed with which your body burns energy at rest is called basal metabolic rate (BMR) and it varies depending on how big you are, your gender, how much you eat, and your activity level. The climate is also a factor.
  • 12.5-25% goes to fueling your muscles, such as exercising or walking up a flight of stairs.
  • %10 goes to the actual processing of food. In other words, it takes some energy to breakdown food to release more energy – just like drills used to find oil use gasoline engines.

These percentages assume you’re only eating as much as you need to balance your BMR, physical exertion, and digestive requirements. If you consume more calories than you expend, the extra energy is stored in your body as fat. This is critical to understand. Though fat is the most calorie-dense nutrient, the fat that we see around our waists is fat created by calories. That means it could be from carbohydrates, alcohols, fats, or even proteins. Though eating a lot of fat will yield a lot of calories (as well as other potential issues such as high cholesterol), most people gain weight because they consume excessive carbohydrates, which are the cheapest and most readily available food source.

Carbohydrates aren’t bad—and neither are fats. In fact, they are necessary. But eat too much of anything and you won’t need to buy an exercise ball for Christmas. You’ll be the size of one. I’ll make this more tangible in the next post – weightloss basics explained.

Nutrition Label Data – Understanding What We Eat

4
1231 days
by in definitions, equations, ethnic, food, goals, nutrition

Nutrition labels aren’t entirely useless—their regulations are surprisingly thorough and they provide basic information about most of the food we eat. Unfortunately, they also legally allow misrepresentation (mostly of serving portions), which the FDA and other regulatory bodies are often unable to validate. The far larger issue is understanding what those numbers and ingredients mean.

Over the course of several weeks, I will build a general nutritional knowledge base. Some bits will be scientific, while others will be more holistic. I will provide specific ways to improve your diet while still eating things you like. I’ll also explain why those methods work.

Here’s some information to build our foundation:

What we consider calories are actually kilocalories, or 1000 calories. One calorie is the amount of energy required to raise 1 gram of water by 1°C. Thus, 1 kilocalorie is the amount of energy required to raise one kilo of water by 1°C. Since a single calorie is quite small, kilocalories [kcal, Calories (uppercase)] are used for measuring energy contained in the food we eat.

Most of what makes up our food can be broken down into three groups: carbohydrates, fats, and proteins. Each gram of carbohydrate yields roughly 4 Calories, and each gram of fat yields 9 Calories. Proteins actually contain 7 Calories per gram, but because the human body cannot convert all amino acids to usable energy, proteins generally yield about the same 4 Calories that carbohydrates do. It should also be noted that alcohol has 7 Calories per gram.

Some foods are entirely contained by one group. Olive oil, for example, is pure fat. If one were to measure 14.235 grams (approximately 1 tablespoon), it would yield roughly 128.115 Calories, or 14.235 grams olive oil * 9 Calories/gram of fat.

Other foods have different combinations of each. For example, some peas I bought have the following properties per serving:

  • 0g fat
  • 12g carbs
  • 5g protein
  • 70 calories total

We can figure out the calories on our own by: (0g * 9Cal/g) + (12g * 4Cal/g) + (5g * 4Cal/g) = 0 Cal + 48 Cal + 20 Cal = 68 Calories, which is rounded up as is allowed by the FDA guidelines.

The balance of these nutrients is also important. It is generally agreed upon that a standard diet should be comprised of roughly:

  • 55-70% carbohydrates
  • 15-30% fats
  • 15-25% proteins

If you eat 65% carbs, 25% fats, then you’d be under your daily protein allotment at 10%. Luckily, these are guidelines. There’s nothing saying you can’t eat more or less of each group. I do often. You will, however, see these figures reflected across many of the world’s cuisines, with some disparity. See for yourself:

Variety is also hugely important in diet in order to get other nutrients such as vitamins, minerals, phytochemicals and enzymes. But that’s another post.

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