My Talk (link to video here) at the American Society of Bariatric Physician's Obesty & Associated Disease Symposium. It was given to a group of doctors, many of which treat their obese patients with a very low calorie diet. It is 15 minutes long, followed by 2 minutes of Q & A. For more on the conference, go here.

"When you're a hammer, everything looks like a nail." No where is this statement more true than in medicine.  A perfect example is in the treatment of type 2 diabetes.

If a doctor suspects their patient may be diabetic, they can run an oral glucose tolerance test (OGTT), in which the patient is given a glucose load, and subsequent blood response is measured to see how effectively the glucose is cleared from the blood. In a non-diabetic, the blood sugar only rises a relatively small amount, as the intact and functional beta cells of the pancreas secrete just the right amount of insulin to reduce the blood sugar levels to normal levels. 

If a person is given an OGTT and their blood sugar spikes more than expected, then by definition they are glucose intolerant. They have failed their OGTT, and cannot tollerate carbohydrates the way a non-diabetic can.

In medical school, we are taught that the primary goal in treating diabetics is to keep blood sugar levels low, and that hemoglobin A1C levels are predictors of further disease progression. There are two major ways to control this blood glucose level, with what we put into our bodies as well as ways to control the blood glucose after it has already risen, such as insulin or other diabetes drugs, such as the alpha-glucosidase inhibitors.

Alpha-glucosidase inhibitors are a category of drug that work by decreasing the absorption of carbohydrates in your gut, resulting in a smaller rise in blood glucose. However, the unabsorbed carbohydrates need to go somewhere, causing the predicted unpleasant side effects of stomach discomfort and diarrhea.

Now instead of taking a drug that will reduce our absorption of carbohydrates, result in various side effects and and cost additional money, why not just eat less of the very foods spiking the blood sugar in the first place? In other words, why would the American Diabetes Association tell us that a diabetic diet should be 40-50% of the calories from carbohydrates, when by definition, these are the vey foods they cannot tolerate? Here is how they describe it on their meal planning page:

It seems equivalent to a person with a peanut allergy slightly lowering their peanut intake and just injecting him or herself with an epinephrine pen after each meal. Why not just stop eating peanuts and avoid the potential side effects of epi injections? Why don't they just not eat the carbohydrates in the first place? After all this was the treatment of diabetes in the pre-insulin era. Here is how Dr. Elliot Proctor Joslin described it in 1893:  

And here is how the Joslin Diabetes Center, named after Dr. Joslin above,  describes it 120 years later:

Diabetes is diagnosed by demonstrating a glucose intolerance and therefore, the first line of therapy should be a reduction in glucose. Why is this logic not the first, most obvious treatment? Of course if the patient refuses, or they reduce their carbohydrates and their blood glucose levels continue to remain elevated, then further therapy is in order.

I believe it is because food is not "a hammer" physicians are equipped with. Medical training in nutrition is essentially absent apart from outdated vitamin deficiencies,  yet doctors are expected to know it, so they default to the USDA's MyPlate for advice and information. This is seen as a constant, unchangeable  variable in treatment of any food related disease, regardless of the etiology, given the label of "diet" or "lifestyle." Just the fact that alpha-glucosidase inhibitors are used as a treatment before a low carbohydrate diet confirms this.

Furthermore, if the patient is given a low fat high carbohydrate diet (as is the standard of care today) to manage their high blood sugar and they do comply with it meticulously, they will very likely need the insulin, alpha-glucosidase inhibitors, and/or metformin to control their daily dose of 180 grams of the very nutrient they cannot tolerate.

Clinical Trials
When you look for clinical trials testing this logic, you see things like this:

The triangle lines are the diabetic patients. The dark triangles represent those on a low carb, ketogenic diet. Their blood glucose and Hemoglobin A1C is significantly lower than those eating a low fat, high carbohydrate diet. This graph also illustrates how in non-diabetics (the circle lines), there is no difference, further supporting the fact that diabetics are carbohydrate intolerant.

Treating Type 2 diabetes with food
Once you have a basic understanding of how the three major macronutrients alter your blood glucose and insulin levels, devising a plan to reduce blood sugar levels becomes simple. 

• Carbohydrates of all kinds raise blood glucose AND insulin
  
• Protein spikes insulin AND DOES NOT seem to spike blood glucose, despite the theoretical ability of the amino acids to be converted into glucose via gluconeogenesis
• Dietary fat does not raise blood glucose OR insulin

Armed with these 3 simple facts, the intuitive treatment of high blood glucose would be: 

1. A decrease in carbohydrates, which spike blood glucose 
2. An increase in protein which acts to secrete insulin and thus reduce blood glucose (essentially acting as giving a patient insulin or sulfonylureas)
3. An increase in dietary fat, which is insulin and blood glucose neutral.
   

And when people eat this way, this is exactly what you see when it is tested:

We have redone the results page, and compiled some stats based on the first 1,100 people to register. We've got thousands of data points to analyze, and present some interesting findings thus far. The large majority of registry members don't count their calories. This practice speaks to one fundamental difference between paleo or low carb, and the traditional advice. Instead of relying on portion size estimation which is very difficult for most, or the false precision of calorie counting, registry members seem to rely on their biology. Once they eliminate grain and flour, they simply eat when they are hungry. No calorie counting. 

Relying on calorie counting as your primary mechanism for determining how much to eat inherently relies on the food industry's abilities to provide accurate information on their food labels. Yet "accurate" is a relative term. The FDA only requires that food manufacturers be within 20% of their actual caloric values. So that 500 calorie lean cuisine spaghetti dish may actually be 600. 

See our new results page!

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Tried a paleo or low carb diet? Join Today and contribute to a better understanding of this way of eating!

The randomized clinical trial offers our best tool for determining the efficacy of an intervention as compared to another. Whether it is a drug trial or diet trial, the devil is in the details. Reading the abstract does not give you the whole story, and it can be profoundly misleading. 

For example, let us assess a popular randomized clinical trial testing the efficacy of different diets, performed by some of the biggest names in diet and obesity research, such as Dr. Frank Sacks and Dr. George Bray.

The conclusion of their study is simple. All diets are created equal. 

This is the headline that makes it into the newspapers and becomes accepted as fact. Why question the results? Dr. Bray and Dr. Sacks and very well respected world-wide for their work; The New England Journal of Medicine is a prestigious journal. No sub-par work would get through the cracks. 


When reading a dietary clinical trial, and assessing its internal validity, there are three major points to keep in mind:

1. How large was the difference between assigned exposures?
2. Is there any evidence that the study subjects followed the diet or intervention they were randomized to?
   
3. When assessing a study testing varying carbohydrate content, is there any difference in triglyceride levels between the groups?

Difference between assigned exposures
The nutrient goals for the four diet groups were:

Low fat, average protein - 20% fat , 15% protein, and 65% carbohydrates 

Low fat, high protein - 20% fat, 25% protein, and 55% carbohydrates 

High fat, average protein - 40% fat , 15% protein, and 45% carbohydrates

High fat, high protein -  40% fat, 25% protein, and 35% carbohydrates

This was how they described it in the paper. Of course, the low fat, average protein group could also be called high carbohydrate group, and the high fat, high protein group could be called low(er) carbohydrate group.

Right away, this study design is somewhat worrisome, since the carbohydrate content of the diets are relatively similar. Determining a 10% difference in macronutrient content is likely unrealistic, since study subjects tend to cheat on their diets and the dietary assessments are subpar. This concern is further compounded by this seemingly innocuous sentence buried in the methods:

"Blinding was maintained by the use of similar foods for each diet."

At first glance this would be great. Blinding adds to the rigor of the study design, by keeping the study subjects in the dark as to which intervention they are receiving. However, in a diet study, this is very difficult. The only way this can be done properly is when foods are chemically modified to contain different nutrients, while still maintaining the same look, smell, and taste of the original food. This has been done beautifully in the Minnesota Coronary Survey, testing the potential benefits of a low saturated fat diet. Although rarely mentioned in the scientific literature, it was a very large, double blinded study that chemically altered the fat composition of various popular foods served to the institutionalized study subjects. (On a side note, this study found absolutely no benefit to eating a low saturated fat diet.)

However, blinding a study comparing different percentages of carbohydrates, protein and fat is essentially impossible without making each intervention very similar.

Is there any evidence that the study subjects followed the diet or intervention they were randomized to?

This is the giant elephant in the room of every dietary clinical trial. It is an enormous problem that nobody really talks about, and it is the major inspiration for developing PhotoCalorie. The "gold-standard" in dietary research in the year 2012 is pen and paper. We have machines that can literally look through your skin and see your organs and bones in vivid detail. We can tell who your parents are, simply by a drop of your spit. Yet when we study obesity, arguably the most important disease that plagues the world today, we use technology from 1812. 

In this particular study, the gold standard was not used. They instead used a 24-hour recall twice throughout the 2 year study in 50% of the patients. In other words, out of the 730 days and 811 study subjects, the primary intervention was only measured on 6 days in 405 people. 

6 DAYS! 0.8% of the days. Assuming they ate 3 meals a day, this means out of 2,190 meals they ate, only 18 of them were reported!

Compounding this unfortunate number is the fact that a 24-hour recall is far from perfect, and people tend to forget what they ate, and report foods deemed healthier more often.

Given all these limitations, here is what the study subjects reported eating. The left three columns correspond to the low fat, average protein group and the right three are for the low fat high protein groups, at 6 months and two years follow up:

As you can see, the macronutrient composition is virtually identical. At 2 years the low fat, average protein group was eating 1531 calories, 53% from carbs, 19.6% from protein, and 26.5% from fat. The low fat high protein group was eating 1560 calories, 51.3% from carbs, 20.8% from protein, and 28% from fat.

When assessing a study testing varying carbohydrate content, is there any difference in triglyceride levels between the groups?

There are other, more objective ways, to assess dietary adherence in such studies. When comparing groups with varying levels of carbohydrates, one excellent tool is the triglyceride levels in the study subjects. Simply stated, when people eat lots of carbs, their triglycerides go up (and their HDL usually goes down). Here is the data from the Sacks study:

The triglyceride levels at 6 months and 2 years are virtually identical. Same with the HDL levels. 

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The authors conclude in the discussion that the  "principal finding is that the diets were equally successful in promoting clinically meaningful weight loss and the maintenance of weight loss over the course of 2 years."

When you combine all these clues together -  the blinded study design, the similar reported macronutrient intake, the identical triglycerides and HDL levels - you come to a dramatic conclusion that explains why all the groups were equally successful: They were all eating the exact same diet!


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Tried a paleo or carb-restricted diet? Join the registry today!