To put it simply: the weight-loss equation is a matter of balancing the amount of energy coming in with the energy going out. If you have more energy or food coming into your body than going out, you gain weight. If you have more energy going out in terms of exercise than you have coming in as food, you lose weight. See, it’s simple! My job here is done; I can take the rest of the year off!
In its essence, it is simple. Up until just a few hundred years ago, all you had to do was follow your instincts and eat the foods your body told you to eat in the quantities that were comfortable for you; that’s it. The daily struggle to find food and survive provided all the exercise we needed to keep us fit until the day we died. What we now call “lifestyle diseases” like heart disease and type 2 diabetes just didn’t exist except as an occupational hazard for kings and queens and extremely wealthy people in the ruling class. Heart disease in these types of people was actually referred to as the “disease of kings.” In 2021 many of the foods we eat today either didn’t exist or were not available in large quantities 100 years ago. There is no longer a daily life-and-death struggle to find food and survive, at least not for much of the American population. I call that living a life out of context.
In our original earth context, our bodies developed instincts and feedback systems that operate subconsciously to guide us to the right foods without having to think about it. If eating the right foods was rocket science, we would have never made it to 2021! You can see this right now by looking at every other animal on the planet; not one animal that grows up free from human contact living in their original earth context is fat, not one. The only animals on the planet that are fat are humans and domesticated pets that we make to eat the same way we do.
When you look at all that has changed in food in the last 100 years, one of the things that stands out is the increase in the amount of energy in food. There are three things that you need to consider when thinking about weight loss and the energy in food; the density or amount of energy in a given amount of food, the amount of satisfaction or fullness that food gives you, and how fast that energy is absorbed or metabolized into your body. We will discuss food density today, food absorption next week, and satisfaction derived from food on both days.
Energy density or caloric density is measured in units of kilocalories (kcal) or kilojoules. One kcal or Calorie is equal to 4.18 kilojoules. Unless you are a dietitian and being very precise about caloric density, you will never see the word kilojoule. I have included it here because that is a term you will find in peer-reviewed journals if you examine the references I provided.
Fat: 9 Calories (37 kJ) per gram
Alcohol: 7 Calories 29 kJ) per gram
Protein: 4 Calories (17 kJ) per gram
Carbohydrate: 3.75 Calories (16 kJ) per gram
Caloric density refers to the number of calories in a given weight of food, usually calories per pound. Foods high in caloric density have a larger number of calories in a measured weight of food, and foods low in caloric density have fewer calories in the same measured weight of food.
Caloric Density Scale
Vegetables: 60-195 calories per pound
Fruit: 140-420 calories per pound
Potatoes, pasta, rice, corn, hot cereals: 320-630 calories per pound
Beans, peas, lentils: 310-780 calories per pound
Breads, bagels, muffins, dried fruit: 920-1,360 calories per pound
Granulated sugar, honey, corn syrup, agave, maple syrup: 1,200 -1,800 calories per pound
Dry cereals, chips, crackers: 1,480-3,200 calories per pound
Nuts and seeds: 2,400-3,200 calories per pound
Oil: 4,000 calories per pound
In general terms, an average-sized man needs about 2000 calories a day, and an average-sized woman needs 1800 calories a day.
Think of your stomach as a box that you fill with things. If that box can hold three pounds of food and you fill it with sugar, nuts and seeds, and oil, it can have 9,000 calories in it. If you fill that box with fruits, vegetables, and potatoes, it would be more like 900 calories. Food that provides calories in excess of what your body needs to function is turned into fat. Fat is an ingenious and efficient way for your body to store energy to use in the future when food may be hard to find. In the context that we live in now, at least in America, food is scarcely hard to find.
You can see how easy it is to consume more calories than you need for a day simply by eating more calorically dense foods. You might not even be full after eating more calories than you need for one day! Eat more foods with low caloric density and limit foods high in caloric density, and you will reduce the chance that you have unburned calories left over that your body will turn into fat!
The measure of fullness or satisfaction derived from food is entirely separate from the concept of caloric density. Simply because food is more calorically dense does not mean that it is associated with a high level of satisfaction.
The fancy word for satisfaction with food is “satiety.” Dietitians have studied this and created something called a “satiety index,” which is a list of foods with a corresponding fullness factor. In a 1995 study published in the European Journal of Clinical Nutrition, thirty-eight foods were measured for a “fullness factor” every 15 minutes for 120 minutes after eating. Foods came from six food categories; fruits, bakery products, snack foods, carbohydrate-rich foods, protein-rich foods, and breakfast cereals. The results will surprise some people. Boiled potatoes with nothing added was far and away the most satisfying food tested! Simply boiled potatoes were 33% more satisfying than the next satisfying food on the list and more than three times more satisfying than white bread, which was close to the center of the list!
The twelve foods providing the most satisfaction and fullness for the longest period of time were boiled potatoes, fish, oatmeal, oranges, apples, brown pasta, beef, baked beans, grapes, whole grain bread (other than wheat), whole wheat bread, and popcorn. The twelve foods providing the least satisfaction and fullness were French fries, cold cereal, white bread, muesli, ice cream, potato chips, yogurt, peanuts, candy bars, doughnuts, cake, and croissants.
Ten of the twelve most satisfying foods contained large amounts of fiber, and seven of them were “whole” or unprocessed food, whereas eleven of the least satisfying foods were processed, and all of those were low in fiber.
There are two types of fiber: soluble fiber, fiber that dissolves in warm water, and insoluble fiber, fiber that does not dissolve in warm water and moves through the intestines pretty much intact. Soluble fiber retains water and expands in the stomach turning to gel during digestion. It slows digestion and nutrient absorption from the stomach and intestine. Soluble fiber is found in foods such as oat bran, barley, nuts, seeds, beans, lentils, peas, and some fruits and vegetables.
In terms of weight loss, soluble fiber does three significant things: it expands and fills your stomach box with low-density food, slows the absorption of nutrients like glucose into your bloodstream, and provides greater satiety or satisfaction.
Fiber is your weight loss secret weapon; it satisfies you, fills your stomach, and slows down sugar absorption.
The glycemic index is a standardized measure of how quickly different foods are metabolized and affect blood sugar. We’ll discuss that next week and talk some more about satiety, environmental context, fiber. We’re also going to discuss nutrient density as opposed to caloric density. See you next week!
Here is the reference for today’s healthy eating tip.
Holt SH, Miller JC, Petocz P, Farmakalidis E. A Satiety Index of common foods. European Journal of Clinical Nutrition. 1995 Sep;49(9):675-90.