My Blog List

Thursday, May 26, 2011

Food Reward: a Dominant Factor in Obesity, Part IV

What is Food Reward?

After reading comments on my recent posts, I realized I need to do a better job of defining the term "food reward".  I'm going to take a moment to do that here.  Reward is a psychology term with a specific definition: "a process that reinforces behavior" (1).  Rewarding food is not the same thing as food that tastes good, although they often occur together. 

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Tuesday, May 24, 2011

Healthy Skeptic Podcast

Chris Kresser has just posted our recent interview/discussion on his blog The Healthy Skeptic.  You can listen to it on Chris's blog here.  The discussion mostly centered around body fat and food reward.  I also answered a few reader questions.  Here are some highlights:
  • How does the food reward system work? Why did it evolve?
  • Why do certain flavors we don’t initially like become appealing over time?
  • How does industrially processed food affect the food reward system?
  • What’s the most effective diet used to make rats obese in a research setting? What does this tell us about human diet and weight regulation?
  • Do we know why highly rewarding food increases the set point in some people but not in others?
  • How does the food reward theory explain the effectiveness of popular fat loss diets?
  • Does the food reward theory tell us anything about why traditional cultures are generally lean?
  • What does cooking temperature have to do with health?
  • Reader question: How does one lose fat?
  • Reader question: What do I (Stephan) eat?
  • Reader question: Why do many people gain fat with age, especially postmenopausal women?
The podcast is a sneak preview of some of the things I'll be discussing in the near future.  Enjoy!

Sunday, May 22, 2011

Fast Food, Weight Gain and Insulin Resistance

CarbSane just posted an interesting new study that fits in nicely with what we're discussing here.  It's part of the US Coronary Artery Risk Development in Young Adults (CARDIA) study, which is a long-term observational study that is publishing many interesting findings.  The new study is titled "Fast-food habits, weight gain, and insulin resistance (the CARDIA study): 15-year prospective analysis" (1).  The results speak for themselves, loud and clear (I've edited some numbers out of the quote for clarity):
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Wednesday, May 18, 2011

Food Reward: a Dominant Factor in Obesity, Part III

Low-Fat Diets

In 2000, the International Journal of Obesity published a nice review article of low-fat diet trials.  It included data from 16 controlled trials lasting from 2-12 months and enrolling 1,910 participants (1).  What sets this review apart is it only covered studies that did not include instructions to restrict calorie intake (ad libitum diets).  On average, low-fat dieters reduced their fat intake from 37.7 to 27.5 percent of calories.  Here's what they found:
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Tuesday, May 17, 2011

Clarifications About Carbohydrate and Insulin

My statements about carbohydrate and insulin in the previous post seem to have kicked up some dust!  Some people are even suggesting I've gone low-fat!  I'm going to take this opportunity to be more specific about my positions.

I do not think that post-meal insulin spikes contribute to obesity, and they may even oppose it. Elevated fasting insulin is a separate issue-- that's a marker of insulin resistance.  It's important not to confuse the two.  Does insulin resistance contribute to obesity?  I don't know, but it's hypothetically possible since insulin acts like leptin's kid brother in some ways.  As far as I can tell, starch per se and post-meal insulin spikes do not lead to insulin resistance.
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Friday, May 13, 2011

Healthy Skeptic Podcast and Reader Questions

Chris Kresser, Danny Roddy and I just finished recording the podcast that will be released on May 24th.  It went really well, and we think you'll find it informative and maybe even practical!

Unfortunately, we only got around to answering three of the questions I had selected:
  1. How does one lose fat?
  2. What do I (Stephan) eat?
  3. Why do many people gain fat with age, especially postmenopausal women?
I feel guilty about that, so I'm going to answer three more right now.

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Tuesday, May 10, 2011

Administrative Note

My blog is being mercilessly ripped off by cheesy feed aggregators that are using my material for commercial gain, often without attribution.  I was able to ignore them when there were only one or two, and when they appeared far down the list on Google searches.  But at this point, there are 20+ rip-off sites that ride my coattails under questionable circumstances, and are getting decent Google rankings, so I've had enough.  I'm changing my feed settings so that I only partially syndicate my posts, and I'm adding a short plagiarism warning to each post.

What that means is that if you're using an RSS reader, you'll have to click through to my blog to read my material in full.  I apologize for the inconvenience, but I don't see any other solution.

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