Diet & Exercise: Digestion takes work, burns calories

Published 5:18 pm Thursday, August 17, 2017

I think all of us who’ve tried to lose weight have at some time heard the adage, “You have to eat to lose fat.” Actually, that’s true, but no one ever tells you what that really means.

Today, I’m going to explain to you exactly what that statement means, and how it works. 

Once you’ve eaten, food doesn’t merely fall through your body. It has to be worked, or processed, if you will, through your body. This not only includes digestion of foodstuffs, but the distribution of nutrients throughout the entire body and the discarding of waste products also. This process involves both “voluntary” and “involuntary” actions by the body.

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To achieve this, calories, which are units of energy, must be burned. In other words, the body must “spend” calories to process any amount of food you eat. Let’s say for instance to utilize any amount of food you eat, your body has to burn 100 calories. You eat a five calorie grape tomato. You have in essence burned, or used up 95 calories just by eating a five calorie grape tomato.

Other water rich vegetables will work much the same way. Pepper, celery, cucumbers, broccoli, lettuce, spinach, mushrooms, cauliflower, cabbage, Brussels sprouts, asparagus, and tomatoes, along with many different vegetables, are referred to as “negative” calorie foods. These negative calories are sometimes referred to as kilocalories. Simply put, negative calorie foods like water rich vegetables require more calories to chew and digest, than they themselves offer. This results in a net loss of calories from fat.

Let’s say that you eat a five calorie grape tomato or other vegetable every hour. Depending on your metabolism, you’ll burn 95 calories or so, of your body fat, every hour just by eating. Also, remember, your body can’t tell the difference between what you “choose” to do, and what you “have” to do, so here’s the best part: If you eat a grape tomato or other water rich vegetable every hour, your body doesn’t know you’re choosing to eat, it just knows food is available. Your body then says to itself, “Food is coming through here all the time, so I don’t have to hold onto all this fat.” Your body will then release some of its fat stores.

Another benefit of consuming vegetables every hour is these foods provide the extra vitamins, minerals, and phytonutrients our bodies need. Eating every hour or so will also help prevent hunger, which will, in turn prevent binge eating.

One thing to be careful of is to not eat starchy vegetables like corn, potatoes, beans, and peas every hour, as they contain a type of sugar called polysaccharides (many sugars). These are often referred to as “complex” sugars or carbohydrates.

Also, while fruit is very healthful, and you should incorporate it as part of a healthy diet, I don’t recommend eating fruit every hour when trying to lose body fat. The reason is that fruit contains two types of sugars called fructose and glucose. Each of these sugars is known as a monosaccharide (one sugar), but when combined, they form a disaccharide (two sugars). The ratios of fructose and glucose are almost the same for fruit and table sugar.

Remember from my earlier articles, we learned that if sugar is in our bloodstream, we can’t dip into our fat stores.

Something of great importance that I will repeatedly tell you through my columns is to always chew your food well (even more than you think you should). This helps digestion and makes nutrient absorption easier on your gastrointestinal (GI) tract.

With fruits and vegetables, it’s particularly important to chew well. Plant cells have cell walls, which are made up of something called “cellulose,” which is microscopically like wood. We can digest it some, but not very well. If we don’t break open these tiny cell walls, we can’t attain nutrients within them. By chewing well, we break open more of these fruit and vegetable cells and receive the goodness inside.

Diet or exercise question? Email me at or text 864-494-6215. David Crocker of Landrum has been a nutritionist and master personal trainer for 29 years.