The Obesity Code: Unlocking the Secrets of Weight Loss (Why Intermittent Fasting Is the Key to Controlling Your Weight)

by Jason Fung

The reason, of course, is that refined carbohydrates are not natural foods but are instead highly processed. Their toxicity lies in that processing.

Longer-term studies of the Atkins diet failed to confirm the much hoped-for benefits. Dr. Gary Foster from Temple University published two-year results showing that both the low-fat and the Atkins groups had lost but then regained weight at virtually the same rate.11 After twelve months, all the DIRECT study patients, including the Atkins group, regained much of the weight they’d lost.12 A systematic review of all the dietary trials showed that much of the benefits of a low-carbohydrate approach evaporated after one year.13

since there was no need for calorie counting. However, following the severe food restrictions of Atkins proved no easier for dieters than conventional calorie counting. Compliance was equally low in both groups, with upwards of 40 percent abandoning the diet within one year.

We continue to eat them simply because they are indulgent. Food is a celebration, and feasting has accompanied celebration throughout human history. This is as true in year 2015 AD as it was in year 2015 BC. Birthdays, weddings and holiday celebrations—what do we eat? Cake. Ice cream. Pie. Not whey powder shakes and lean pork. Why? Because we want to indulge. The Atkins diet does not allow for this simple fact, and that doomed it to failure.

THE CARBOHYDRATE-INSULIN HYPOTHESIS, the idea that carbohydrates cause weight gain because of insulin secretion, was not exactly wrong. Carbohydrate-rich foods certainly do increase insulin levels to a greater extent than the other macronutrients. High insulin certainly does lead to obesity. However, the hypothesis stands incomplete.

Total and percentage carbohydrate intake in China far exceeds the other nations. Sugar intake in China, however, is extremely low compared to the other nations. Japan’s carbohydrate intake is similar to that of the U.K. and the U.S., but its sugar consumption is far lower.

So the carbohydrate-insulin hypothesis was not incorrect, but clearly something else was going on. Total carbohydrate intake was not the entire story.

Indeed, many primitive societies that eat mostly carbohydrates have very low obesity rates.

Comparing the Kitavans to his native Swedish population, Dr. Lindeberg found that despite a diet that was 70 percent carbohydrate (unrefined), the Kitavans had insulin levels below the 5th percentile of the Swedes.16 The average Kitavan native had an insulin level lower than 95 percent of Swedes. The body mass index of young Kitavans averaged 22 (normal) and it decreased with age.

Clearly, the carbohydrate-insulin hypothesis is an incomplete theory, leading many to abandon it rather than try to reconcile it with the known facts.

Insulin and obesity are still causally linked. However, it is not at all clear that high carbohydrate intake is always the primary cause of high insulin levels.

critical piece of the puzzle had been neglected. Specifically, sugar plays a crucial role in obesity, but how does it fit in? The missing link was insulin resistance.

Time dependence in obesity is almost universally understood but rarely acknowledged. Usually, obesity is a gradual process of gaining 1 to 2 pounds (0.5 to 1 kilogram) per year. Over a period of twenty-five years, though, that can add up to 50 extra pounds (23 kilograms). Those who have been obese their entire lives find it extremely difficult to lose weight.

Likewise, the carbohydrate-insulin hypothesis makes no allowance for duration of obesity: reducing carbohydrates should cause weight loss, regardless of how long you’ve been overweight. But that’s not true either.

So we must acknowledge the phenomenon of time dependence. Obesity at age seventeen has consequences that reach decades into the future.

insulin resistance. Insulin resistance is Lex Luthor. It is the hidden force behind most of modern medicine’s archenemies, including obesity, diabetes, fatty liver, Alzheimer’s disease, heart disease, cancer, high blood pressure and high cholesterol. But while Lex Luthor is fictional, the insulin resistance syndrome, also called the metabolic syndrome, is not.

THE HUMAN BODY is characterized by the fundamental biological principle of homeostasis.

What happens in the case of insulin resistance? As discussed before, a hormone acts on a cell as a key that fits into a lock. When insulin (the key) no longer fits into the receptor (the lock), the cell is called insulin resistant. Because the fit is poor, the door does not open fully. As a result, less glucose enters. The cell senses that there is too little glucose inside. Instead, glucose is piling up outside the door. Starved for glucose, the cell demands more. To compensate, the body produces extra keys (insulin).

Why do we care? Because insulin resistance leads to high insulin levels, and as we’ve seen, high insulin levels cause obesity.

The total thermogenic effect of food over twenty-four hours for both the grazing and gorging strategies is the same: neither yields a metabolic advantage. Eating more frequent meals does not aid in weight loss.13

The third myth is that eating frequently keeps blood glucose from becoming too low. But unless you have diabetes, your blood sugars are stable whether you eat six times a day or six times a month.

Millions of dollars are spent to give children snacks all day long. Then millions more are spent to combat childhood obesity. These same kids are berated for getting fat.

We never consider the implications of the drastic changes we have made in meal timing. Think about it this way: In 1960, we ate three meals a day. There wasn’t much obesity. In 2014, we eat six meals a day. There is an obesity epidemic.

In 2009, nutritional standouts such as Cocoa Puffs and Frosted Mini Wheats were still on the Heart Check list. The 2013 Dallas Heart Walk organized by the AHA featured Frito-Lay as a prominent sponsor.

The financial-disclosures section of some papers published in journals and on the web can run for more than half a page. Funding sources have enormous influence on study results.3 In a 2007 study that looked specifically at soft drinks, Dr. David Ludwig from Harvard University found that accepting funds from companies whose products are reviewed increased the likelihood of a favorable result by approximately 700 percent!

Furthermore, we cannot simply eat our usual diet and add some fat or protein or snacks and expect to lose weight. Against all common sense, weight-loss advice usually involves eating more.

HEALTH PROFESSIONALS NOW heavily promote snacking, which previously had been heavily discouraged. But studies confirm that snacking means you eat more.

Although we think it’s a universal truth, it’s really only a North American custom. Many people in France (a famously skinny nation) drink coffee in the morning and skip breakfast. The French term for breakfast, petit déjeuner (little lunch) implicitly acknowledges that this meal should be kept small.

It is simply not necessary to eat the minute we wake up. We imagine the need to “fuel up” for the day ahead. However, our body has already done that automatically.

This effect is called the dawn phenomenon, and it has been well described for decades. Many people are not hungry in the morning. The natural cortisol and adrenalin released stimulates a mild flight-or-fight response, which activates the sympathetic nervous system. Our bodies are gearing up for action in the morning, not for eating. All these hormones release glucose into the blood for quick energy. We’re already gassed up and ready to go.

Morning hunger is often a behavior learned over decades, starting in childhood.

The main problem in the morning is that we are always in a rush. Therefore, we want the convenience, affordability and shelf life of processed foods.

Does breakfast make you hungry? If you eat a slice of toast and drink a glass of orange juice in the morning—are you hungry an hour later? If so, then don’t eat breakfast. If you are hungry and want to eat breakfast, then do so.

ONE OF THE most pervasive pieces of weight-loss advice is to eat more fruits and vegetables, which are undeniably relatively healthy foods. However, if your goal is to lose weight, then it logically follows that deliberately eating more of a healthy food is not beneficial unless it replaces something else in your diet that is less healthy.

What is not explicit is that increased intake should displace less healthy foods in our diet.

EXCESSIVELY HIGH INSULIN resistance is the disease known as type 2 diabetes. High insulin resistance leads to elevated blood sugars, which are a symptom of this disease. In practical terms, this means that not only does insulin causes obesity, but also that insulin causes type 2 diabetes. The common root cause of both diseases is high, persistent insulin levels. Both are diseases of hyper-insulinemia (high insulin levels). Because they are so similar, both diseases are beginning to be observed as a syndrome, aptly termed diabesity.

Socioeconomic status has long been known to play a role in the development of obesity in that poverty correlates very closely with obesity.

The basic premise of this argument is that food is more delicious in 2010 than in 1970 because food scientists engineer it to be so. We cannot help but overeat calories and therefore become obese. The implication is that hyper-palatable “fake” foods are more delicious and more rewarding than real foods, but that seems very difficult to believe. Is a “fake,” highly processed food such as a TV dinner more delicious than fresh salmon sashimi dipped in soy sauce with wasabi? Or is Kraft Dinner, with its fake cheese sauce, really more enticing than a grilled rib-eye steak from a grass-fed cow?

be blunt, the rich can afford to buy food that is both rewarding and expensive, whereas the poor can afford only rewarding food that is cheaper.

For those dealing with poverty, food needs to be affordable. Some dietary fats are fairly inexpensive. However, we do not, as a general rule, drink a cup of vegetable oil for dinner. Furthermore, official government recommendations are to follow a low-fat diet. Dietary proteins, such as meat and dairy, tend to be relatively expensive. Less expensive vegetable proteins, such as tofu or legumes, are available but not typical in a North American diet. This leaves carbohydrates. If refined carbohydrates are significantly cheaper than other sources of food, then those living in poverty will eat refined carbohydrates.

with hefty agricultural subsidies. But not all foods get equal treatment. Figure 12.26 indicates which foods (and programs) receive the most in subsidies.

In 2011, the United States Public Interest Research Groups noted that “corn receives an astounding 29 percent of all U.S. agricultural subsidies, and wheat receives a further 12 percent.”7

Unprocessed carbohydrates, on the other hand, receive virtually no financial aid. While mass production of corn and wheat receives generous support, the same cannot be said for cabbage, broccoli, apples, strawberries, spinach, lettuce and blueberries.

The government is subsidizing, with our own tax dollars, the very foods that are making us obese. Obesity is effectively the result of government policy.

It is noteworthy that, in the 1920s, sugar was relatively expensive. A 1930 study9 showed that type 2 diabetes was far more common among the wealthier northern states compared to the poorer southern states. As sugar became extremely cheap, however, this relationship inverted. Now, poverty is associated with type 2 diabetes, rather than the other way around.

Sugar consumption rose steadily from 1977 to 2000, paralleled by the rising obesity rates. Diabetes followed with a time lag of ten years.

THE WORST OFFENDER, by far, is the sugar-sweetened drink—soft drinks, sodas and, more recently, sweetened teas and juices.

Coca Cola had faced nine consecutive years of sales decline as health concerns about sugar mounted. Concerned with declining health and ballooning waistlines, people were less inclined to drink a toxic, sugary brew.

The result has been a diabetes catastrophe. In 2013, an estimated 11.6 percent of Chinese adults have type 2 diabetes, eclipsing even the long-time champion: the U.S., at 11.3 percent.

Daily consumption of sugar-sweetened drinks not only carries a significant risk of weight gain, but also increases the risk of developing diabetes by 83 percent compared to drinking less than one sugar-sweetened drink per month.