LOOPTECHS

Corrections to the New Review Paper on Dietary Fat and Cardiovascular Risk

On March 26, 2014 By jammy // No comments:

The meta-analysis by Chowdhury et al. raised quite a furor from certain segments of researchers and the popular media. I find this reaction interesting. I usually write about obesity, which is a topic of great interest to people, but my post about the review paper received more than twice my usual traffic. People whose findings or opinions are questioned by the paper are aggressively denouncing it in the media, even calling for retraction (1). This resembles what happens every time a high-profile review paper is published that doesn't support the conventional stance on fatty acids and health (e.g., Siri-Tarino et al. [2], which despite much gnashing of teeth is still standing*). I'm not sure why this issue in particular arouses such excitement, but I find it amusing and disturbing at the same time. This kind of reaction would be totally out of place in most other fields of science, where aggressive public media outbursts by researchers are usually frowned upon.

As it turns out, the critics have a point this time. Significant errors were uncovered in the original version of the meta-analysis, which have been corrected in the current version (3). These include the following two errors, one of which alters the conclusion somewhat:

The outcome of one observational study on omega-3 fatty acids was reported as slightly negative, when it was actually strongly positive. This changes the conclusion of the meta-analysis, making it somewhat more favorable to omega-3 consumption for cardiovascular protection.
The authors left out two studies on omega-6 fatty acids. These didn't change the overall conclusions on omega-6.

Book Review: Your Personal Paleo Code

On March 25, 2014 By jammy // No comments:

Chris Kresser has been a major figure in the ancestral health community for some time now. It's funny to recall that I was actually one of his first readers, back in the early days of his blog when it was called The Healthy Skeptic and the audience was small. Chris's readership rapidly eclipsed mine, and now he's in high demand for his ability to convey ideas clearly and offer practical solutions to important health concerns.

He recently published a book titled Your Personal Paleo Code, which also happens to be a New York Times bestseller. The primary goal of the book is to help you develop a diet and lifestyle that support health and well-being by starting from a generally healthy template and personalizing it to your needs. Let's have a look.

Introduction

Kresser opens with the poignant story of his own health problems, which began with an infectious illness in Indonesia and several courses of antibiotic therapy. After years of struggling with the resulting symptoms, trying a variety of diets, and finally accepting his condition, he was unexpectedly able to recover his health by adopting a personalized Paleo-like diet that included bone broth and fermented foods.

Why Paleo?

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Food Reward Friday

On March 14, 2014 By jammy // No comments:

This week's lucky "winner"... the Taco Bell waffle taco!!

The Ultimate Detox: Your Kidneys

On March 06, 2014 By jammy // No comments:

The specter of unseen, unspecified toxins eroding our health is worth many millions of dollars in the United States and abroad. Companies offer "detox" supplements, beverages, and creams that supposedly rid us of supposed toxins, despite a complete lack of evidence that these products do anything at all*. This comes from an industry that excels at creating boogeymen and offering costly solutions for them.

If your wallet needs to lose weight, then these products are highly effective, otherwise it's probably best to save your money. Here's why.

The body is equipped with an extremely advanced system for excreting toxins. The kidneys are part of this system, and their design is genius. The basic functional unit of the kidney is the nephron, and the average kidney contains about a million of them. Nephrons have two major parts: a renal corpuscle and a renal tubule.

A nephron. In this image, the Bowman's capsule and glomerulus make up the renal corpuscle, and the proximal/distal tubules and the loop of Henle (#1-3) make up the renal tubule. Note the network of blood vessels (capillaries) that allow the transfer of water and other goodies from the tubule back into the blood. Image source.

The renal corpuscle is the interface between the blood and the fluid that will eventually become urine. Blood is filtered by a fine "sieve" of cells that prevents everything larger than a small protein from passing into the renal tubule. Red blood cells, platelets, and most proteins stay on the blood side, while small proteins such as albumin, minerals, urea, glucose, water, and almost anything that would be considered a toxin** are allowed through into the renal tubule.

The renal tubule is a long tube that re-absorbs everything in this filtered blood that the body wants to keep. Water, minerals, albumin, glucose, amino acids, and other useful molecules are re-absorbed. Everything else ends up as urine and is excreted.

Can you see the genius of this design? Urine is blood, minus all the good stuff. Everything that isn't specifically recognized by the body as useful is excreted by default, no matter what it is. The body doesn't have to recognize each of the thousands of foreign compounds that make their way into our circulation each day. These substances are all out the door, by default.

Are you impressed by your kidneys yet? If not, consider this. Your kidneys filter your entire blood volume roughly 70 times per day. The reason you don't have to pee a liter a minute is that urine volume is reduced by 99 percent due to water reabsorption in the renal tubules.

This is why most drugs have to be taken on a regular basis, often several times per day. In concert with the detoxification enzymes of the liver, which tend to make drugs easier for the kidneys to excrete, the kidneys rapidly reduce the circulating concentration of drugs simply by excreting everything they don't recognize as useful.

Can a detox product improve upon 500 million years of kidney evolution***? I have my doubts.

* Exception: chelation therapy offered by a licensed medical practitioner for actual, diagnosed heavy metal poisoning. Second exception: strategies that use the word "detox" loosely to refer to removing unhealthy foods from the diet.

** Toxins tend to be very small-- either small organic molecules or minerals such as arsenic. Larger toxins such as proteins are uncommon in the circulation because proteins are generally not absorbed by the digestive tract. Toxic proteins have to be injected or otherwise directly introduced into the circulation, e.g. by a snake bite or a bacterial infection. But if you're bitten by a rattlesnake, I hope your first line of treatment won't be a detox kit from your local supplement store.

*** Kidneys are present in hagfish and lampreys, the most "primitive" living vertebrates.

Food Reward Friday

On February 28, 2014 By jammy // No comments:

This week's lucky "winner"... Kirkland Signature Cashew Clusters!!

WHS reader Brad Dieter mentioned these on Facebook the other day:

Nutrition tip of the day. Do not buy Cashew Clusters from Costco. You will eat an entire bag in one fell swoop. Sweet, salty, crunchy, and calorie dense, the perfect storm in Stephan Guyenet's model of overeating. I have n=1 data as proof.

n=1 quickly turned into n=6 as other people chimed in, including myself. I can attest to the fact that Cashew Clusters are like crack. Here's more evidence from their Amazon reviews:

"Addiction with less guilt!" These things are SO freaking good!!!... I'm eating some right now and I am having trouble keeping my hand out of the bag long enough to write this review!

"Delicious". I gave this as a gift to my girl friend... She loved it ! Heard there wasn't much sugar either. Seems the nuts were crispy and the clusters were very addicting, in a nice way. It lasted only for 6 days. [SG- each bag contains 4,800 calories]

"Buy these and you will be hooked for life!" One word "NUMMY!"... Very addicting.

Cashew Clusters are only about 11 percent sugar by calories, with the other 89 percent of calories coming from whole nuts and seeds. They're probably a healthy snack if you can eat them in moderation. Can you?

Snacktime in My Kitchen

On February 26, 2014 By jammy // No comments:

Here is a photo of all visible food in my kitchen:

Along the back wall, we have glass containers of raw nuts, unsalted roasted nuts, grains, and legumes. It's easy and attractive to organize your dry foods using inexpensive 2 quart Ball jars. They also have the advantage of being moth-proof. On the left, we have fresh fruit and a few onions. On the far left in the background is our hand-cranked conical burr grinder, for occasional coffee (Skerton).

If I walk into my kitchen between meals, the only food available to eat without doing any cooking or reheating is unsalted nuts and fresh fruit. There is no other snack food in the kitchen. No chips, cookies, bars, popcorn, snack mix, candy, or anything else that's tempting and easy to grab and devour.

When it's mealtime, we eat good home-cooked food. When it isn't mealtime, we don't have anything available that we would eat without feeling genuinely hungry. If we do feel genuinely hungry, fresh fruit and unsalted nuts make a satisfying snack.

This is the way of my people.

What's the point? Eliminating tempting food cues from our surroundings and creating small barriers to food consumption decreases the quantity of food we eat while increasing the quality. Engineering a food environment that discourages eating for reasons other than hunger helps match food intake to the body's true energy needs, favoring leanness and health.

Mindless Eating

On February 13, 2014 By jammy // No comments:

You think you're in control of your eating behavior-- but you aren't

In 2005, Brian Wansink's research group published a remarkable study that demonstrates the powerful unconscious influence of the food environment on our consumption (1).

Volunteers were invited to a test kitchen to eat bowls of tomato soup for lunch. Each person was given a bowl containing 18 ounces of soup-- but there was a catch. Half the volunteers were given custom-made soup bowls that partially refilled as they ate, such that the soup level dropped more slowly.

5 Easy and Effective Ways to Eat Less

On February 11, 2014 By jammy // No comments:

Why do we overeat? Why is it hard to lose fat once we've gained it? Is there a way to comfortably and sustainably eat less and lose fat?

I recently did an interview with Armi Legge of Evidence Magazine that gives an overview of my thinking on these topics-- based on a large and compelling body of research that rarely reaches popular media sources in useful form.

At the end of the interview, Armi asks me to list my top five tips for reducing calorie intake. Enjoy!

5 Easy and Effective Ways to Eat Less

Mysteries of Energy Balance and Weight Loss

On February 06, 2014 By jammy // No comments:

How to Lose Weight Effortlessly

You've probably seen this claim many times: a pound of fat contains 3,500 kilocalories (kcal). A slice of toast is 80 kcal. All you have to do is forego one slice of toast per day-- just a few percent of your total calorie intake-- and you will lose 8.3 lbs of fat per year. Fat loss is so easy!

This reasoning is extremely common both in the popular media and among researchers. Here's an example from the book Mindless Eating, by researcher Brian Wansink:

...the difference between 1,900 and 2,000 calories is one we cannot detect, nor can we detect the difference between 2,000 and 2,100 calories. But over the course of a year, this mindless margin would either cause us to lose ten pounds or to gain ten pounds. It takes 3,500 extra calories to equal one pound. It doesn't matter if we eat these extra 3,500 calories in one week or gradually over the entire year. They'll add up to one pound.

This is the danger of creeping calories. Just 10 extra calories a day-- one stick of Doublemint gum or three small Jelly Belly jelly beans-- will make you a pound more portly one year from today. Only three Jelly Bellys a day.

According to this reasoning, if I reduced my calorie intake by 80 kcal per day, I'd become skeletal in two years and vanish in a puff of smoke within 10 years*. All from a meager 3 percent reduction in calorie intake!

What's wrong here?

NutriScience Seminar in Lisbon with Lindeberg, Fontes, and Bastos

On February 05, 2014 By jammy // No comments:

My friend Pedro Bastos has asked me to spread the word about a seminar he's organizing in Lisbon titled "Evidence and Evolution-based Nutrition". It will include Staffan Lindeberg, Maelan Fontes, and Pedro Bastos-- three quality researchers in the area of evolutionary health-- I'm sure it will be interesting. Here's the flier:

Public Talk at the University of Virginia on Friday, January 17

On January 12, 2014 By jammy // No comments:

This Friday, I'll be giving an invited lecture at the University of Virginia, my undergraduate alma mater. I was kindly invited by a medical student named Robert Abbott, and it worked out well because I was already traveling to Charlottesville.

The talk will be titled "Why Do We Overeat? A Neurobiological Perspective". Here's the teaser:

Obesity is a leading cause of morbidity and mortality in industrialized nations, yet this is a relatively recent phenomenon. In the United States, increasing obesity prevalence has paralleled a gradual increase of daily energy intake. Why do most Americans eat more than we used to, and more than we need to maintain a lean state, despite negative consequences? This presentation will touch on the neurobiology of action selection, the neurobiology of energy homeostasis, and why our central nervous system hardware may not be up to the task of constructively navigating the modern food environment.

The talk will be attended by medical students, but I also hope to have some doctors and researchers show up, as well as people from the broader Charlottesville community. It will be a thought-provoking talk regardless of your background, and it will touch on some of my own work.

The talk will be held in the main medical school auditorium, MEB 3110, on Friday, January 17 at noon. You can find driving directions and parking information by following this link. You'll probably have to park in a parking garage, either the Lee Street or Central Grounds garage (directions in the link).

For a map of the UVA health system, follow this link. The Medical Education Building is number 44 on the map, and the talk will be in room MEB 3110 on the 3rd floor of the building.

See you there!

Free e-Book and Ideal Weight Program 2.0 Announcement

On January 01, 2014 By jammy // No comments:

I'm happy to announce that we're releasing a free e-book titled Why do We Gain Fat, and How do We Lose it? An Introduction to the Science of Body Fat, by Dan Pardi and myself. This is a slimmed-down version of the longer, fully referenced e-book we offer as part of the Ideal Weight Program. In it, we provide a succinct overview of the science of body fat gain and loss, and the evidence base for our program. It also contains a schematic that ties together the various concepts in visual form. You can download it from the Dan’s Plan site by following this link to our program overview page.

Ideal Weight Program 2.0 Upgrades

Over the last year, Dan and I have been working hard to improve the Ideal Weight Program, both in response to user feedback and our own ideas for development. Here are some of the new features we offer in 2014:

Four-week meal plans and shopping lists for the FLASH diet and the Simple Food Diet, as requested by Ideal Weight Program users. This is in addition to the recipes and cooking guides we already provide.
The Protein Unit system. Research suggests there's an optimal amount of protein for appetite control and fat loss, depending on your height, weight, gender, and physical activity level. Our fat loss diets are high in protein, but how do you know you're getting the right amount? We've created a calculator that does it for you automatically, and explains how to apply your personalized Protein Unit value easily and intuitively using real food.
Diet plates. These are visual guides to following our diets, based loosely on the intuitive USDA MyPlate design.
Cheat sheets. Put these on your fridge to remind yourself of your diet and lifestyle guidelines, and daily protein unit goal.
Updated guidance. We've refined a few things in the diet guidance documents.

At a time of year when many people want to shed excess holiday pounds and start down a leaner, healthier path, we offer the Ideal Weight Program 2.0. The program comes with a 30-day no-questions-asked refund policy so you can try it without risk. We think you'll love this program, but if it doesn't work for you, we're happy to refund your purchase price.

Financial disclosure: I receive a portion of the revenue from the sale of the Ideal Weight Program. I do not receive revenue from the sale of other products associated with Dan's Plan or the Ideal Weight Program (such as the Fitbit, cooking tools, and other programs).

Does the Vitamin and Mineral Content of Food Influence Our Food Intake and Body Fatness?

On December 30, 2013 By jammy // No comments:

The Claim: We Overeat Because Our Diet is Low in Vitamins and Minerals

We know that animals, including humans, seek certain properties of food. Humans are naturally attracted to food that's high in fat, sugar, starch, and protein, and tend to be less enthusiastic about low-calorie foods that don't have these properties, like vegetables (1). Think cookies vs. plain carrots.

In certain cases, the human body is able to detect a nutritional need and take steps to correct it. For example, people who are placed on a calorie-restricted diet become hungry and are motivated to make up for the calorie shortfall (2, 3). People who are placed on a low-protein diet crave protein and eat more of it after the restriction is lifted (4). Humans and many other animals also crave and seek salt, which supplies the essential minerals sodium and chlorine, although today most of us eat much more of it than we need to. At certain times, we may crave something sweet or acidic, and pregnant women are well known to have specific food cravings and aversions, although explanations for this remain speculative. Research suggests that certain animals have the ability to correct mineral deficiencies by selecting foods rich in the missing mineral (5).

These observations have led to a long-standing idea that the human body is able to detect vitamin and mineral (micronutrient) status and take steps to correct a deficit. This has led to the secondary idea that nutrient-poor food leads to overeating, as the body attempts to make up for low nutrient density by eating more food. In other words, we overeat because our food doesn't supply the micronutrients our bodies need, and eating a micronutrient-rich diet corrects this and allows us to eat less and lose body fat. These ideas are very intuitive, but intuition doesn't always get you very far in biology. Let's see how they hold up to scrutiny.

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