On Weight Control

Definition of Obesity: “…the presence of excess body fat that threatens or affects health”

Although weight gain has long been looked at for decades as simply a caloric imbalance–more calories ingested compared to calories burned–for which the advice has been simply to eat less and exercise more, there is increasing evidence that not all calories are created equal, and that obesity as simply a function of “gluttony and sloth” may not be accurate or fair.

Although genetic factors do play a large role, heritability is not destiny.

Reduced energy intake is effective in weight reduction, but surprisingly, such diets generally do not work well in the long term:

  • “Dietary therapy remains the cornerstone of [obesity] treatment and the reduction of energy intake continues to be the basis of successful weight reduction programs,”  

observes The Handbook of Obesity, a textbook edited by George Bray, Claude Bouchard and W. P. T. James, three of the most respected names in obesity research, and first published in 1998. It then goes on to acknowledge that the results of such therapy “….are known to be poor….”

Regardless of body weight or weight loss, an increased amount of exercise increases health—you can be overweight and generally healthy.

Physical activity or exercise in sufficient dose aids in long term weight maintenance, but is not usually the primary driver of weight loss.

Although low fat diets have been used successfully for weight loss, they have been shown to be less effective than low carbohydrate diets in now 18 randomized control trials.

Eating more whole foods is optimal nutrition. Refined (processed) foods tend to be more concentrated in calories, usually are reduced in or devoid of fiber, water, and micronutrient content, cause quicker absorption of calories, more likely to cause spikes of blood sugar and serum insulin, a tendency to overeat, and a decreased effect on satiety.  These foods also usually have undesirable additives, and the missing nutrients may actually drive you to eat more.  Where possible eat foods without labels.  And understand the glycemic index of foods, for the reasons stated below.

Most convenience foods are convenient, but they are often have a high glycemic index and they are not usually nutritious.  They may be particularly unhealthy for those who are relatively carbohydrate intolerant.  If your great grandmother wouldn’t have recognized it (as author Michael Pollan suggests in his book, In Defence of Food), it is probably not a real food!

Refined and starchy carbohydrates—foods containing easily accessible simple sugars—drive serum insulin levels higher, which in turn cause triglycerides (fats) to be stored.  Therefore prioritize complex, unprocessed carbohydrates when eating carbohydrates.  For sensitive individuals, this may also include avoiding some high glycemic fruits.  Most weight loss programs get participants to avoid foods that elevate blood sugar, and therefore stimulate insulin to store fat.

The principle of weight loss through the avoidance of refined carbohydrates has been repeated in a long list of diet best sellers.  Here are excerpts from several of them:

Dr. John McDougall,  The McDougall Plan (1983):
The most serious problem with the simple sugar foods is not their effect on blood sugar or insulin levels, but that they are mostly empty calories….. (Yet): “Obesity can result from the high concentration of calories found in unprotected simple sugars (4 calories per gram).  Consumption of simple sugars leads to an elevation of serum triglycerides (blood fats) in some people. High triglyceride levels may aggravate diabetes, hypoglycemia, heart disease, and problems associated with poor circulation.  Even whole fruits can have an adverse effect on triglyceride levels because of their content of simple sugars.”  Alcohol, caffeine, refined cereal and grains, and polyunsaturated and saturated fats will also raise triglyceride levels.  Cholesterol and blood pressure are increased slightly by replacing complex carbohydrates with simple sugars.”

Dr. Dean Ornish, from Eat More, Weigh Less (1993):  
(p.26): “Besides regulating your blood sugar level, insulin plays an important role in fat metabolism.  Because insulin increases the secretion of lipoprotein lipase, an enzyme that increases the uptake of fat from your bloodstream into fat in your body’s cells, when your body produces more insulin, you are more likely to convert dietary calories into fat…. Insulin also plays a key role in increasing cholesterol synthesis. When your insulin levels rise, your liver makes more of an enzyme called HMG-CoA reductase which, in turn, causes your body to make more cholesterol.  ….. Besides increasing your cholesterol level, insulin enhances growth and proliferation of arterial smooth muscle cells.  These smooth muscle cells help to clog up your arteries and can lead to heart attacks…… Insulin tends to distribute weight in your upper body, making you apple-shaped instead of pear-shaped….. Upper-body fat–being an apple–is much more harmful to your health than being a pear….most of the health risks of being overweight are due to fat in your abdomen.”
Dr. Joel Fuhrman, from Eat to Live (2003): 
(p.27): Liquid calories,without the fiber present in the whole food, have little effect at blunting our caloric drive.  Studies show that fruit juice and other sweet beverages lead to obesity in children as well.  If you are serious about losing weight, don’t drink your fruit–eat it. There is no substitute for whole foods…..
(p.33): If you want to lose weight, the most important foods to avoid are processed foods: condiments, candy, snacks, and baked goods; fat-free has nothing to do with it.  Almost all weight-loss authorites agree on this-you must cut out the refined carbohydrates, including bagels, pasta, and bread.  As far as the human body is concerned, low-fiber carbohydrates such as pasta are almost as damaging as white sugar.  Pasta is not health food–it is hurt food.”
Dr. Arthur Agatston, from The South Beach Diet (2003):
(pp 52-53): “…the equation behind most obesity is simple:  The faster the sugars and starches you eat are processed and absorbed into your bloodstream, the fatter you get.  Therefore anything that speeds the process by which your body digests carbohydrates is bad for your diet, and anything that slows it down is good. 
Consider that loaf of sliced white bread.  First the wheat is stripped of the bran and fiber.  Then it is pulverized into the finest white flour. The baking process puffs it up into light, airy slices of bread.  No wonder your stomach makes such quick work of it.  A slice of white bread hits your bloodstream with the same jolt you’d get by eating a tablespoon of sugar right from the bowl!  Whereas real, old-fashioned bread… puts your stomach to work.  It too, is made of wheat, but the grains haven’t been processed to death.   You may even see pieces of grain and bran there in the bread.  It contains starches, which are just chains of sugars, but they are bound up with the fiber, and so digestion takes longer.  As a result, the sugars are released gradually into the bloodstream.  If there is no sudden surge in blood sugar, your pancreas won’t produce as much insulin, and you won’t get the exaggerated craving for more carbs.  This is crucial to the understanding of how your body operates:  The more food is preprocessed, the more fattening it will be.”
(p.62): “Eating bad carbohydrates–especially highly processed ones–creates cravings for more carbs, which ultimately is responsible for our epidemic of obesity.”
(p.57):…..So, eating an apple a day is still a prescription for well-being.  But drinking its juice is not.”
 p.55: “Fiber is not the only thing that gets in the way of sugars.  Fats and proteins also slow the speed at which your stomach does its job on carbs.”
(p.77): “When we eat fats, it is also insulin’s job to transport the fatty acids from the bloodstream into the body’s tissues, where they belong, to be used immediately for fuel or stored for future use in the form we know as triglycerides or simply as fat.”
(p.80): “As we delegate more and more of ourfood preparation to fast food restaurants and food manufacturers, its quality has deteriorated–not just in its taste but in its fiber and nutrient content.  In a sense, food manufacturers have begun the digestion process for us.  Until quite recently, we did not appreciate that processed foods were bad and have contributed to our epidemic of obesity.”
Richard Gallop, from The Glycemic Index Diet (2002):

Check out these links, and subscribe if you are interested:

Dr. Arya Sharma is currently the president of the Canadian Obesity Network, and you can find his blog at: http://www.drsharma.ca/  Check out his comments on the use of BMI as a valid indicator of excess body fat at: http://www.drsharma.ca/accuracy-of-bmi-for-diagnosing-obesity-2.html

Dr. Yoni Freehoff is a recognized expert in obesity in Ottawa, and a long time blogger on healthy diets.  See his site, “Weighty Matters” here. Drs. Sharma and Friedhoff published a book on obesity management in 2010; Dr. Friedhoff is expecting to publish a new book shortly. http://www.weightymatters.ca/2013/01/the-new-england-journals-obesity.html


Interesting new lines of evidence are emerging about causes of obesity.  Recently, it has been shown that bowel microflora can affect the development of obesity in humans and in mice. Another study of overweight young adults demonstrated that isocaloric diets that were low in fat were much less likely to stimulate both total and resting energy expenditure than diets that were low in carbohydrates, suggesting that not all calories are the same.  A randomized control study lasting 2 years revealed that a low carbohydrate diet and a Mediterranean diet were as or more effective in weight loss and various health parameters than was a low-fat diet.  These findings confirmed what was shown in the A to Z Diet study in 2007, where the Atkins diet had more favorable outcomes with every measure (including weight loss) than did the Zone Diet or the Ornish diet. The lead researcher at Stanford reviewed his findings in this video.