Always Hungry?

This is fantastic book written by David Ludwig, M.D., Ph.D. Dr. Ludwig is a practicing endocrinologist at Boston Children’s Hospital, professor of pediatrics at Harvard Medical School, and professor of nutrition at Harvard School of Public Health.

Chapter 1 Notes

The original Food Guide Pyramid, published in 1992, exemplified the low-fat diet craze. The pyramid advised us to avoid all types of fat because they contain twice the calories of other major nutrients. Instead, we were told to load up on carbs – 6-11 servings of bread, cereal, crackers, pasta, and other grain products.

Fat cells are more than just passive storage sites for excess calories. They take in or release calories only when instructed to do so by external signals – and the master control is insulin.

Too much insulin causes weight gain, whereas too little causes weight loss.

Overeating doesn’t make us fat. The process of becoming fat makes us overeat. Hunger and overeating are the consequences of an underlying problem.

When something triggers fat cells to suck up and store too many calories from the blood, fewer calories are available to fuel the energy needs of the body. The brain perceives this as a problem and unleashes the starvation response, including measures to increase calories intake (hunger) and save energy (slower metabolism). Eating more solves this “energy crisis” but also accelerates weight gain.

One obvious source of the problem is highly processed carbohydrates which digest rapidly, raising insulin levels excessively and programming fat cells to hoard calories.

Stress, sleep deprivation, and sedentary habits have also forced fat cells into calorie-storage overdrive.

The conventional calorie balance approach fails because it’s focused on the wrong target. The fundamental problem isn’t having too many calories in the body; it’s having too few in the right place, circulating in the bloodstream and available for our immediate needs.

The solution is to change what we eat, not how much, and retrain our fat cells.

  1. Turn off the starvation response by eating whenever you’re hungry.
  2. Tame your fat cells with a diet that lowers insulin levels, reduces inflammation, and redirects calories to the rest of your body.
  3. Integrate physical activities, sleep, and stress relief into your lifestyle to improve metabolism.

The central concept of the book is that while cutting calories will decrease weight for a short while, the body resists by increasing hunger and slowing metabolism. Sooner or later we succumb, and weight tends to pop back up. In contrast, improving the quality of what we eat will reprogram fat cells to store fewer calories, in effect reducing the “body weight set point.”

Conventional thinking (wrong):

To lose weight, simply eat less and move more.

Calories In  –  Calories Out  =  Calories Stored

Fat9 calories/gram
Carbohydrates4 calories/gram
Protein4 calories/gram

Chapter 2 Notes

In the 1970s, prominent nutrition experts began recommending that everyone follow a low-fat diet, in the belief that eating less fat would automatically help lower calorie intake and prevent obesity. This began the biggest public health experiment in history. Unfortunately, this experiment didn’t turn out well. In the 1960s, Americans ate more than 40 percent of calories as fat. Today, fat intake approaches the government-recommended limit of 30 percent, but rates of obesity have skyrocketed (from <15% in 1960 to around 35% today).

Women’s Health Initiative

  • The world’s largest clinical diet trial
  • 50,000 women assigned to a low-fat diet or a control group for 8 years
  • The study was fundamentally flawed with a clear bias in favor of the low-fat diet
  • Main results released in 2006: Women in the low-fat group lost a maximum of only 5 pounds compared to the control group, and this small difference decreased to 1 pound by the end of the study. Furthermore, there was no reduction in rates of cancer, diabetes, or heart disease.

Based on meta-analysis of several such studies, it’s possible that the most widely recommended method for four decades to reduce calorie intake has done more harm than good.

Fifty years ago, 13 percent of adults in the United States had a BMI in the obese range. Today, that figure is 35 percent. An additional 34% are overweight.

Four stages of the obesity epidemic

In Stage 1, obesity rates increased rapidly during the late twentieth century. But it may take years for complications like diabetes or fatty liver to develop in someone with obesity (Stage 2) and many additional years for those complications to cause a life-threatening event like a heart attack, stroke, cirrhosis, or kidney failure (Stage 3).

Astoundingly, almost one in two American adults now have diabetes or prediabetes and one in three have fatty liver. By middle age, many people take a cocktail of powerful drugs to lower blood pressure, cholesterol, and blood sugar, attempting to stave off heart attack and stroke. As the first generation with epidemic obesity reaches old age, cases of neurodegenerative diseases like Alzheimer’s are rising precipitously. 

In Stage 4, the epidemic propagates from one generation to the next at an accelerating rate. Being heavy in childhood leads to obesity later in life.

In 2005, Ludwig and his colleagues predicted that obesity would shorten life expectancy in the United States for the first time since the Civil War – by an amount equal to the effects of all cancers combined – unless something is done about it [the obesity epidemic]. This prediction has not yet come to pass, but worrisome warning signs are already present. Between 1961 and 1983, life expectancy increased in a relatively consistent fashion throughout the U.S., and no county had a significant decline. However, between 1983 and 1999, life expectancy decreased significantly in 11 counties for men and 180 counties for women. Of particular concern, the counties that showed relative or absolute decreases correspond closely with those most severely affected by the obesity epidemic, located predominantly in the South and Midwest. These trends have continued through the last decade.