Not All Calories Are Created Equal — ‘ISOCALORIC’ (Not) ‘ISOMETABOLIC’

Over the past 35 years, the number of calories we ingest has increased significantly. More importantly, the quality of the calories we take in has dramatically plummeted.

The nutritional value of the food we eat and drink greatly determines how our metabolism works to keep us healthy. Every day we are challenged to incorporate good calories into our diet and put aside the bad. That’s not so easy since unhealthy calories and harmful chemicals seem to be hidden from plain sight when we shop for food.

A calorie measures the energy in the food we eat. The notion that all calories are equal is false. “A calorie is not a calorie.” The calories in a sugar sweetened beverage are not the same as the calories in fruits and vegetables. Our body metabolizes them differently with different outcomes.

Isocaloric but Not Isometabolic

Clinical researcher and Pediatrician, Dr. Robert Lustig, in his talk, “Sugar, The Bitter Truth”, explains that foods (or beverages) A and B might have the same number of calories (isocaloric) but the way the body metabolizes (processes) the food can have different health consequences (not isometabolic).

For example, if you have A, 120 calories of glucose (two slices of white bread) and compared it to B, 120 calories of sugar in 8 ounces of orange juice, the body metabolizes them differently.

  • A) The cells process 80% of the glucose calories in bread (96 calories) and use them as fuel in the body. The liver processes 20% of the remaining calories (fat, glucose and protein) and they are stored in the liver as glycogen. The glycogen, when needed, is broken down into glucose and made available to the body to avoid the blood glucose level becoming too low.
  • B) The opposite occurs with the sugar in orange juice. The120 calories of sugar in the orange juice are composed of 50% fructose and 50% glucose. The liver metabolizes 80% of the calories and the cells 20%.

The calories of fructose can only be metabolized by the liver and it doesn’t make glycogen. If the liver is overloaded with fructose, it can cause several diseases

Lustig uses shorthand when he states foods are “Isocaloric but not isometabolic”. What are the health implications?

Health Implications

The over indulgence of sugar and processed foods in time will have negative effects on our metabolism and cause illness. The chemical composition of table sugar (sucrose) and High Fructose Corn syrup (H.F.C.S) found in sugary drinks and processed foods are essentially the same

Table sugar is 50% fructose and 50% glucose. H.F.C.S. is 55% fructose and 45% glucose. Lustig zeros in on the excess consumption of sucrose and H.F.C.S. as being public enemies to good health. He emphasizes that not all calories are created equal and notes that of the over 600,000 thousand food items in the United States, 77% of them are loaded with sugar or sugary ingredients.

Fructose is processed by the liver and the liver transforms it into fat. Over time, with the continued overconsumption of sugar, processed foods and in particular fructose, fatty liver disease develops which leads to increased levels of uric acid, insulin resistance, type 2 diabetes and the Metabolic Syndrome (see below).

Who you are depends, in part, on the quality of food you put into your body and how it energizes you. Nature helps out by providing fiber in fruits, vegetables and other foods to counteract unhealthy calories.

Some of the benefits of fiber: it lowers cholesterol levels, slows the absorption of sugar in the G.I. tract thereby helping to control blood sugar levels.and helps to prevent us from overeating. Juice extracted from fruits has no fiber and is basically fructose. And fast food according to Lustig is “fiberless food”. The takeaways, not all calories are created equal. Food should make us feel better, energize us, not sap vitality from us nor lead to sickness. There are good and bad protein and fats. . Good and bad carbohydrates. We can give nature a helping hand the next time we go shopping or out to a restaurant by shifting the diet to one low in sugar, high in fiber and free of processed foods.

Glossary

Metabolic syndrome

According to the NIH, you must have three of the five risk factors listed below to be diagnosed with Metabolic Syndrome.

  • High blood pressure
  • High fasting blood sugar, too much sugar in the blood (or you’re on medication to treat blood sugar)
  • A large waistline. For men, a waist that measures greater than 40 inches around and for women greater than 35 inches around. This is also called abdominal obesity or having an “apple shape” abdomen.
  • A high triglyceride level, means having too much fat in the blood (or you’re on medicine to treat high triglyceride).
  • A low HDL cholesterol level (or if you’re on medication to treat low HDL). HDL is at times called “good or healthy” cholesterol.

Fructose

Earl Kooi and Richard Marshall were the first to make High Fructose Corn Syrup in 1957. Dr. Y.Takasaki, a Japanese scientist, created H.F.C.S in the mid 1960’s. It was introduced into the American markets in 1975. Because it was sweeter and cheaper, it became the number one substitute for sugar in America and eventually in the world.


References

Lustig, Robert, MD; Sugar The Bitter Truth 7/27/2009; UCSF

Lustig, Robert H; Fructose: “Alcohol Without the Buzz”; Advances in Nutrition, March, 2013

Make Your Calories Count, US Food and Drug Administration; 12/16/201

Marshall, R.O; Kooi, E>E; Enzymatic Conversion of D-Glucose to D-Fructose; Science, 1957

Webb, Denise, PhD; Farewell to the 3500-Calorie Rule; Today’s Dietician, Nov 2014

Anticaglia, Joseph R; Metabolic Syndrome and Wellness Stay Off the Farm; HC Smart, 2016

Anticaglia, Joseph R; What’s It All About — Calories, Weight Loss. Basal Metabolic Rate; HC Smart, 2017

This article is intended solely as a learning experience. Please consult your physician for diagnostic and treatment options.