What does insulin resistance have to do with overweight and weight loss?

We observe all the time that some people seem to be able to eat anything and not gain weight, and others eat very little and are heavy.  The calories in/calories out dogma denies that this phenomenon exists, but we all know it does.  At the Packard pediatric weight control program, one of the most difficult things for the children there to handle was the fact that it seemed their peers could eat anything they wanted, including chips, candy, and soda, and be slim.  And they were right.

How is this possible?  How an individual will respond to the typical American diet is dictated by how insulin sensitive or insulin resistant they are.  The typical American diet is high in carbohydrates.  Carbohydrates cause the body to produce insulin to keep blood sugar in a normal range.  (An equal amount of energy consumed as fat causes virtually no change to insulin levels).  Some individuals are sensitive to insulin–they can process a given amount of carbohydrate with relatively little insulin release.  But some are insulin resistant–they require a lot of insulin to process that same amount of carbohydrate.

Insulin is also known in any biology textbook as “the fat storage hormone.”  Can you guess which individual is going to gain weight from the typical American diet?

Relative insulin sensitivity or resistance also explains how an individual is going to respond to different sorts of eating plans designed for weight loss.  The insulin sensitive individual can lose weight on a low fat, low calorie plan or on a low carb plan.  But the insulin resistant individual will find it very hard to lose weight on a low fat, low calorie plan:

“Insulin Resistance and Diet Success

In 2007, Gardner et al published a randomized, controlled trial called the A-to-Z Study involving 4 diets lasting a year given to groups of obese women[43]. At one end of this diet spectrum was the ‘Ornish diet’ which is very high in complex carbs and very low in fat. At the other end was the ‘Atkins diet’ (i.e., low carbohydrate). After 6 months, the women on Atkins had lost significantly more weight, but after 12 months they were still lower but not significantly so. Interestingly, blood pressure and HDL cholesterol were significantly better on low carbohydrate than any of the other diets, and this beneficial effect remained significant out to 12 months. After publishing this initial paper in JAMA, Dr. Gardner went back and examined his data based upon the subjects’ insulin levels before they started dieting. When the women on each diet were divided into three subgroups (tertiles) based on baseline insulin resistance, the results were striking. In the low carbohydrate diet group, weight loss was similar in the most insulin sensitive (11.7 lbs) and insulin resistant (11.9 lbs) women. However weight loss with the high carbohydrate (Ornish) diet was much greater in the insulin sensitive (9.0 lbs) than the insulin resistant (3.3 lbs) women. Thus the most insulin sensitive sub-groups of women experienced a similar weight loss when assigned diets either high (9.0 lbs) or low (11.7 lbs) in carbohydrate In contrast, the sub-groups that were insulin resistant fared very poorly when assigned a diet high in carbohydrate (3.3 lbs lost) compared to a low carbohydrate diet (11.9 lbs). Specifically, those women with insulin resistance lost almost 4-times as much weight when dietary carbohydrates were restricted[44].”

Phinney, Stephen; Volek, Jeff (2011-07-08). The Art and Science of Low Carbohydrate Living: An Expert Guide to Making the Life-Saving Benefits of Carbohydrate Restriction Sustainable and Enjoyable (pp. 85-86). Beyond Obesity LLC. Kindle Edition.

They may lose some, like Juliana did, because a low fat, low calorie plan is almost certainly also a lower carb plan.  But the insulin resistant people are going to be hungrier than the insulin sensitive people on an Ornish-type plan.  Why?  The more insulin, the more the cells get the message to store available energy as fat.  The more that is stored as fat, the less is available to use, and the sooner that person will be hungry again.

I have already taken Dr Dean Ornish to task for publishing a misleading opinion piece in The New York Times blasting low carb eating plans.  He would also do well to pay attention to his patients who cannot comply with his eating plan because of hunger, or don’t lose much weight even if they do comply.   He might learn something.

 

 

Low Fat attacks Low Carb

Dr. Dean Ornish, in an opinion piece in the New York Times, slammed low carb eating plans with a review of a recent study containing so many half-truths it is hard to know where to start.  It is exactly this sort of misleading information that kept my daughter overweight, tired, and often sad for so many years before I figured out how to help her.

The study tested the efficacy of a low fat diet, a low glycemic diet, and a low carb diet in maintaining weight loss.  The Atkins-type diet has been shown repeatedly now to produce the most weight loss (and in an interesting twist, in this study it showed the most energy expenditure), but Ornish wants to argue that just because it makes you thinner doesn’t mean it makes you healthy.  Ornish reviews evidence that his eating plan has successfully reversed severe coronary artery disease and halted the progression of Type 2 diabetes.  In contrast, Ornish reports, accurately, that the low carbohydrate eating plan in this study resulted in higher levels of C-reactive protein and cortisol, both associated with increased risk of heart disease and other chronic diseases.  He fails to mention that the study showed that the low fat diet produced the worst outcomes for insulin resistance, triglycerides, and HDL (the good cholesterol), while the Atkins-style diet produced the best.  Furthermore, there are many studies of low carb diets that do show improvements in C-reactive protein: “Not all low carb diet studies have shown significant reductions in biomarkers like CRP or IL-6, but many have. We suspect the variable results seen in other studies may be due to both questionable compliance with the assigned diet, plus the diets not being low enough in carbohydrate to achieve these anti-inflammatory effects.”

Phinney, Stephen; Volek, Jeff (2011-07-08). The Art and Science of Low Carbohydrate Living: An Expert Guide to Making the Life-Saving Benefits of Carbohydrate Restriction Sustainable and Enjoyable (p. 85). Beyond Obesity LLC. Kindle Edition.

He fails to cite any of the voluminous evidence that Atkins-type eating plans have also reversed coronary artery disease and type 2 diabetes, as well as many other chronic health conditions.  See these descriptions of research results from “The Art and Science of Low Carbohydrate Living” (and for more information I highly recommend reading the whole book):

“Type-2 Diabetes

Concurrent with this and subsequent cases that we generated in Vermont, Dr. Bistrian completed a series of seven closely monitored cases in Cambridge/Boston[120]. It was his very low carbohydrate ketogenic (VLCKD) diet protocol that we used in the case study above. All seven of the subjects in his published report were obese, insulin-using type-2 diabetics, and all were able to be withdrawn from insulin therapy (up to 100 units per day) in an average of 7 days after starting the VLCKD. All of these subjects went on to lose a considerable amount of weight, an achievement that is decidedly uncommon in diabetics who are using injected insulin.”

Phinney, Stephen; Volek, Jeff (2011-07-08). The Art and Science of Low Carbohydrate Living: An Expert Guide to Making the Life-Saving Benefits of Carbohydrate Restriction Sustainable and Enjoyable (pp. 193-194). Beyond Obesity LLC. Kindle Edition.

“In 1994, the Lyon Diet Heart Study [48] was terminated prematurely at 27 months due to a dramatic decrease in mortality in the group that consumed a 40% fat Mediterranean-type diet compared to a group that was prescribed the American Heart Association’s ‘prudent diet’. This dramatic difference in heart disease and overall mortality occurred despite the fact that there were no differences in the two groups’ LDL-C responses to the diets.”

Phinney, Stephen; Volek, Jeff (2011-07-08). The Art and Science of Low Carbohydrate Living: An Expert Guide to Making the Life-Saving Benefits of Carbohydrate Restriction Sustainable and Enjoyable (p. 91). Beyond Obesity LLC. Kindle Edition.

Ornish then cites evidence from another study that low carb, high protein diets promote coronary artery disease.  But the Atkins diet is not a high protein diet.  Most of the calories from an Atkins type eating plan come from fat.  Ornish does this for a living.  I’m just a part-time blogger.  I don’t believe he doesn’t know the difference between a high protein and a high fat diet.

Ornish cites evidence from the Nurses Health Study that red meat consumption, which he calls “a mainstay of the Atkins diet,” is associated with “increased risk of premature death, as well as greater incidence of cardiovascular disease, cancer, and Type 2 diabetes.”  And that may well be true.  Lots of things are bad for you in the presence of too much carbohydrate.  I’m pretty sure most of those nurses were eating a typical high carb American diet, not a low carb one.

Ornish ignores the carbohydrate restriction of the Atkins eating plan, and that is where all the action is, as I’m sure he is aware.  Even fat, the real mainstay of the Atkins diet, is bad for you with too much carbohydrate.  In the presence of too much carbohydrate, insulin will direct your body to store the fat calories as fat, rather than burn them for fuel as your body would do on the low carb plan.

Ornish shows a puritanical streak, arguing that low carb eating plans are popular because people want to hear that “cheeseburgers and bacon are good for you.”  On the other side of the opinion spectrum, low carb eating plans are criticized as being too restrictive:  “how long do you want to keep eating that bacon double cheeseburger, hold the bun, thank you?”  (In the small world of this research, the second comment happens to come from Dr David Ludwig, who is also the author of the study Ornish is reviewing.  Ludwig advocates a low glycemic diet).  Clearly, low carb eating plans can’t win:  they’re both too yummy and too limited at the same time, depending on which eating plan you favor.

So What is Ornish pushing?  A mostly plant-based, “low in fat,” low in unhealthful carbs and red meat eating plan.  He reviews the results of a randomized controlled trial of his program.  Participants lost an average of 24 pounds over a year, and maintained a 12 pound weight loss over 5 years.  Sorry, but weight loss of 24 pounds in a year, and gaining half of that back over 5 years, is not that impressive.

Ornish recycles the idea that by replacing fat with carbs, you can eat the same amount of food and still lose weight.  That might be true, if you are successful in eating the same amount of food.  But on a low fat, high carbohydrate diet, (even of “healthy” whole grain carbs), you’re apt to be hungrier than on a high fat, low carb diet, and you won’t be able to hold your food intake constant.

Juliana lost 6 pounds in 10 weeks on a diet similar to Ornish’s.  To comply with the philosophy of the Packard weight loss program, we went heavily into a plant-based low fat diet, without any refined carbohydrates.  She was constantly hungry.  Then we switched to a low carb plan.  She lost 3.5 pounds in a week (most of the early weight loss is water—the first thing that happens on a low carb plan is that you dump excess retained water).  Now she is losing 2 pounds steadily per week, without hunger.

I know Juliana is an “n” of 1; our experience is not a randomized controlled trial.  If Ornish’s patients are satisfied, that’s great for them.  But I don’t see the need for him to publish a misleading attack on low carb plans to tout his program.  If you find that an Ornish-type eating plan works for you and your children, that’s great.  But if you find it doesn’t, then consider joining the low carb club.

 

Juliana asked to stay in the soccer game

I was refereeing Juliana’s soccer game on Saturday.  I noticed that she played all four quarters, but I didn’t really think anything of it.  Then yesterday she told me that she was scheduled to be out in the fourth quarter, but she asked if anyone else wanted to sub out so that she could stay in.  It was a hot day, and Juliana’s team was getting crushed–the outcome wasn’t in doubt.  Juliana wanted more practice.

Parents of low energy kids–imagine your kid voluntarily staying in a soccer game–asking to stay in a soccer game through the fourth quarter.  That’s the miracle of low carb eating.

Fat moms make fat babies; and thin, high-carb eating moms might make fat kids too…

Juliana is the oldest of three kids, and the only one of my three kids who was ever overweight.  Indeed, at the moment, my son Teddy is technically underweight, with a BMI in the 3rd percentile.

When I was pregnant with and nursing Juliana, I ate a vegetarian diet.  When I was pregnant with her sister Molly, I had an overwhelming desire for chicken, and abruptly stopped eating vegetarian after 18 years.  So I got to wondering whether there might be a relationship between what I ate while pregnant and nursing and Juliana’s metabolism and ability to handle carbohydrates versus her siblings.

And there could be.  Fat mothers produce fatter babies; diabetic mothers (whose blood sugar is on average higher than non-diabetic mothers) produce fatter babies.  And the incidence of fat babies is increasingly dramatically, in step with the increase in obese and diabetic adults.

“The probable explanation is that as women of childbearing age get heavier and more of them become diabetic, they pass the metabolic consequences on to their children through what is known technically as the intrauterine environment. The nutrient supply from mother to developing child passes across the placenta in proportion to the nutrient concentration in the mother’s bloodstream. If the mother has high blood sugar, then the developing pancreas in the fetus will respond to this stimulus by overproducing insulin-secreting cells. “The baby is not diabetic,” explains Boyd Metzger, who studies diabetes and pregnancy at Northwestern University, “but the insulin-producing cells in the pancreas are stimulated to function and grow in size and number by the environment they’re in. So they start over functioning. That in turn leads to a baby laying down more fat, which is why the baby of a diabetic mother is typified by being a fat baby.”

Taubes, Gary (2007-09-25). Good Calories, Bad Calories (Kindle Locations 8167-8174). Random House, Inc.. Kindle Edition.

Juliana wasn’t actually a fat baby.  But her intrauterine environment was with me eating a vegetarian diet, which was necessarily higher carb than when I switched to being an omnivore with Molly and Teddy’s pregnancies.  She was also nursed for several years with me eating a vegetarian diet.  I’m not diabetic, but that doesn’t mean Juliana didn’t suffer the consequences of my high-carb eating style:

“There’s no reason to think that the hormonal and metabolic consequences of high blood sugar—from what James Neel in 1982 called the “excessive glucose pulses that result from the refined carbohydrates/ over-alimentation of many civilized diets”—do not pass from mother to child through the intrauterine environment, whether the mother is clinically diabetic or not.”

Taubes, Gary (2007-09-25). Good Calories, Bad Calories (Kindle Locations 8189-8192). Random House, Inc.. Kindle Edition.

I can’t prove that my eating style contributed to Juliana’s carb sensitivity and subsequent overweight–but it’s an interesting association that she is the only one of three kids who experienced my high-carb eating style and she’s the only one with excess weight.

Really, you don’t need carbohydrates

I keep running across comments like this one, from “Ending the Food Fight,” by David Ludwig, MD, PhD: “[Low carb diets] do produce more weight loss than low-fat diets, but only temporarily.  After one year, people following both diets gain back nearly all of the weight they lose.  These approaches ultimately fail because our bodies and our minds rebel against severe restriction of any major nutrient, whether fat or carbohydrate.  (How long do you want to keep eating that bacon double cheeseburger, hold the bun, thank you?)”

First off, I assume Dr. Ludwig is referring to people who stop eating low carb and then gain back their weight, which of course, they will.   Continuing to eat low carb at the level of carbohydrates your body can handle, which might be 20, 50, or 100 grams a day, is one of the most successful ways to maintain weight loss.

Second, why does Dr. Ludwig assume that all macronutrients (fat, protein, carbohydrate) are equal, or equally required?  They’re not.  Carbohydrates in the form of agricultural grains did not even exist in the human diet until several thousand years ago.  People who eat a “Paleo/Primal” or “Caveman” diet eschew all grains, legumes, and dairy.  They eat mostly vegetables and meats, and a small amount of fruit.  (Modern fruit is larger, sweeter, and available for more of the year than ancient fruit).

It’s maybe not surprising then, given that they are so new, that carbohydrate is the only macronutrient your body does NOT require.  It can get along just fine on zero carbohydrate, unlike fat or protein.  ”…animal foods contain all of the essential amino acids (the basic structural building blocks of proteins), and they do so in the ratios that maximize their utility to humans.* 94 They also contain twelve of the thirteen essential vitamins in large quantities…The thirteenth vitamin, vitamin C, ascorbic acid, has long been the point of contention. It is contained in animal foods in such small quantities that nutritionists have considered it insufficient and the question is whether this quantity is indeed sufficient for good health.”

Taubes, Gary (2007-09-25). Good Calories, Bad Calories (Kindle Locations 6551-6557). Random House, Inc.. Kindle Edition.

 It turns out that the tiny quantity of vitamin C in animal foods is sufficient, provided you aren’t eating a diet high in carbohydrate.  In other words, you only need to supplement the vitamin C available from animal foods if you eat a lot of non-animal foods.

Taubes, Gary (2007-09-25). Good Calories, Bad Calories (Kindle Location 6630). Random House, Inc.. Kindle Edition.

Another argument you sometimes hear is that dietary carbohydrates are required to provide glucose for the brain.  But this is not so.  The liver manufactures the fuel it needs from other nutrients if dietary carbohydrate falls below a certain level.

Taubes, Gary (2007-09-25). Good Calories, Bad Calories (Kindle Locations 6492-6498). Random House, Inc.. Kindle Edition.

And what about Dr. Ludwig’s opinion that people can’t live forever without the hamburger bun?  A great effect of a low carb eating plan is that the desire for carbohydrates greatly diminishes, or disappears altogether.  And in sensitive individuals, eating the bun after getting used to the low carb style will probably make you feel sick and tired.  Go ahead and try it once, like Juliana did with a scoop of ice cream, and you won’t be so tempted the next time.

Dr. Ludwig instead advocates a low-glycemic diet, which I bet works better than a low fat diet for many people.  But in sensitive individuals like Juliana it would not work because it includes more fruit and grains (even if they are whole grains!) than her system can handle.