Lyle McDonald Interview Part 3 (Carbohydrates)

Posted: October 5, 2008 in Interviews


STEVE: It’s about time we discuss some nutrition. We know that it’s easier for an obese individual to lose fat than a relatively lean individual. I’ve always operated under the ideal of starting with a balanced, calorically controlled diet containing foods that are enjoyed by the client when working with obese people. The rigidity of most plans is too great for the individual who has such a long road ahead to adhere to for any appreciable length of time. Once the balanced, calorically controlled diet is in place and habitual, then you can start manipulating the various macronutrients. In other words, build a meaningful foundation, if you will, before toying around with the smaller variables.

Assuming this foundation is in place, what suggestions would you have with regards to carbohydrates given the population in question? You’ve written more than I’m sure you desire about low carb vs. high carb diets and I’m waiting for you to e-slap the hell out of me for bringing up this topic. Do you have any general advice for the person looking to lose 100+ lbs beyond the typical: “Toy around with the different variables until you find something you can consistently adhere to that works”?


LYLE:  In the same way that fat was demonized in the 80’s, I’d say that dietary carbohydrates are currently getting the ‘blame’ for obesity these days.  Of course, these things always go in cycles anyhow and in another 10 years, we’ll be back to dietary fat being the problem.  Now, there is some truth to this only that we live in a world where massive amounts of refined carbohydrates can be consumed cheaply and easily.  And of course carbs are tasty.  So, they can be quite easy to overeat.  I’d note that the impact of carbs has been blamed on various things over the years.  High-fructose corn syrup is a current whipping boy for obesity and books are always blaming insulin for ‘making people fat’.  In reality, I think it’s a simpler explanation: carbs are easy to overeat and certain types of carbs are even easier to overeat than others (consider that high-fructose corn syrup is found in a lot of non-diet sodas and it turns out that the body doesn’t sense liquid calories as well as solid calories; those people drinking 64 oz regular sodas from the mini-mart are adding thousands of calories to their daily diet that their bodies aren’t sensing, so they don’t adjust their other food intake down). 

In any case, there’s no doubt that essentially any calorically restricted diet will ‘work’ in at least the short-term (long-term maintenance is a separate issue and, in my opinion, as, if not more important).  However, there is also the empirical fact that people clearly do respond relatively better or worse to different dietary patterns.  As well, recent research is starting to examine the impact of diet (especially in terms of the carbohydrate content) relative to insulin resistance/sensitivity.

Some quick definitions for readers might be in order here.  Insulin sensitivity refers, essentially, to how well or how poorly the body responds to the signal sent by the hormone insulin (a storage hormone released primarily in response to carbohydrate consumption).  Cells that are highly insulin sensitive respond well to small amounts of insulin; cells that are insulin resistant don’t.  Insulin resistance, ultimately, causes the body to tend to produce too much insulin when carbs are eaten and this can cause a number of different problems that are either health or weight related.  If nothing else, the body’s overproduction of insulin can often cause blood glucose to crash back down, which tends to stimulate hunger.  So insulin resistant people who are eating a lot of refined carbohydrates (especially without sufficient fiber, fat and protein) tend to get blood sugar swings that make them hungry throughout the day.  The end result is that they eat more calories.

Now, in general, when obesity develops, so does insulin resistance; I’d note that this isn’t a guarantee; you can find skinny people who are highly insulin resistant and overweight individuals with good insulin sensitivity.  In any case, recent work has started to examine different dietary approaches in terms of their carbohydrate content relative to the level of insulin resistance.  In one small pilot study, dieters were categorized as either insulin sensitive or insulin resistant and then either put on a high or low-carbohydrate diet.  So there were four groups.

1. Insulin sensitive: high carbs

2. Insulin sensitive: low carbs

3. Insulin resistant: high carbs

4. Insulin resistant: low carbs

And while all groups lost weight (calories were the same), the insulin sensitive group did better with high carbs and the insulin resistant group did better with low-carbs.  This is right in line with previous empirical observations.

Anyhow, back to the question: given that most people are overconsuming refined carbohydrates in the modern world, and given that insulin resistance often goes hand in hand with being overweight, reducing carbohydrate intake is usually a good thing from a health and weight perspective.  

The next question might be how much carbs should be reduced.  While extremely low-carbohydrate diets are always in vogue to some degree or another, as you sort of allude to above, they may not be necessary or beneficial for everyone.  Frankly, for most people, if they’d start by simply finding a little bit of balance, I think that would make the most sense.  Getting adequate amounts of lean protein, adequate dietary fat and moderate amounts of less refined carbohydrates and doing so at every meal would do most of the work.  By reducing the total carbohydrate quantity (and changing the quality), along with increasing protein, fat and fiber blood sugar control is improved along with hunger and fullness.  As well, by keeping some carbohydrates in the diet, more variety is possible which tends to improve adherence.  Finally, various bits of research have found that moderate fat intakes improve both dietary adherence and are probably healthier overall than extremely low- or high-fat diets.

Now, in more extreme cases of insulin resistance, or in situations where people find themselves unable to eat moderate amounts of carbohydrates (for either psychological or physiological reasons), a complete restriction of carbohydrates (such as an Atkins, Protein Power or some such) diet may be required, at least initially.  Not only can this help with weight loss (assuming, of course, people don’t eat too much; calories always count) very low-carbohydrate diets can improve various aspects of insulin resistance and health.  As well, taste buds change over time; empirically I’ve seen folks who seemed almost ‘addicted’ to refined carbohydrates lose their taste for them after some period of time on a very low-carbohydrate diet.  This often allows them to add carbohydrates back into the diet after starting with the more extreme restriction of the very low-carb approach.


STEVE:  That’s good stuff, Lyle.  I have to laugh because when Lyle answered this question, he apologized for the rambling.  If most trainers or authors explained stuff half as well as Lyle “rambles”, we’d all be much better off!

Sticking with this topic, I’d also like to branch out to one side question.   I’m sure some of our readers are going to read your last paragraph about those who are really insulin resistant and think to themselves, “How do I know if I am of this group and need something like Atkins?”  Do you have any commentary with regards to this hypothetical question?


LYLE:  Well, the only truly accurate way of determining if someone is insulin resistant is with blood work.  Fasting blood glucose or insulin can be tested or, if necessary, something called an oral glucose tolerance test can be run.  This requires drinking a certain amount of straight glucose and then measuring the blood glucose response over several hours.

However, there are a few somewhat indirect ways of knowing if someone is insulin resistant. They are far from perfect but they will give some indication.  Perhaps the biggest indicator is that, after a high carb meal (especially if it doesn’t contain sufficient amounts of protein, fiber and dietary fat), energy levels are extremely inconsistent.  Individuals who are insulin resistant overproduce insulin and when a lot of carbs are eaten; this can cause blood sugar to crash below normal.  This not only causes energy to wane but often causes rebound hunger (leading the individual to consume yet more refined carbohydrates).  In contrast, insulin sensitive individuals tend to show much more stable energy and blood sugar levels when they eat a bunch of carbohydrates, because their bodies handle it better.  Frankly, this is probably the single easiest thing to track: if eating a bunch of carbohydrates (especially refined carbohydrates) makes you feel terrible a little while afterwards, odds are you’re a bit insulin resistant and will do better by reducing carbohydrates and increasing protein and (healthy) fats.

Many people who are insulin resistant also find that a lot of carbohydrates makes them feel bloated and puffy, this is especially true with leaner athletes.


STEVE:  Thanks for that follow-up. 

Suffice it to say that much of the carb-phobia backing many of today’s pre-packaged diets exists solely to restrict caloric intake.  If you limit or completely eliminate one of the three macronutrients we consume, it isn’t hard to see that caloric intake is most likely going to drop. 

Keeping in mind what Lyle talks about here, there is reason for consideration when determining how you should handle carbohydrates in your diet.  I think the take-home message is, “Don’t fear carbs just because there are a lot of quacks running around rooting them to the cause of obesity.”  We’re all locked to the confines of thermodynamics and unless you overeat carbs (too many calories), you aren’t going to get fat.  Concurrently, some of us might do much better in terms of adherence and progress if we limit the quantity and improve the quality of the carbohydrates we consume.




Stick with us as Lyle and I will be discussing why, in his mind, diets tend to fail in a couple of days.  As always, if there are follow up questions relative to any of these blog entries, please feel free to send your questions either to one of the emails to the right or as a ‘comment’ under the specific blog post in question.

Best to all.

  1. […] « Lyle McDonald Interview Part 3 (Carbohydrates) […]

  2. […] I found the following phrase on Body Improvements, and it tickled me immensely: “e-slap the hell out of me” – an interviewer of Lyle […]

  3. Cezary says:

    >moking, drinking, exercise and eating habits are all difficult to change; this >suggests to me that there is some aspect of human behavior that generally >makes changing habits difficult.

    is it? your knowledge about new ways is astonishing up-to-date, but maybe you should pay more interest into some techniques that enables habits changing to be instant and easy

    shouldn’t it be a part of what you are working currently?

  4. Cezary says:

    i ment your new ways in dieting approach of course

  5. I’m not sure I understand your question. Are you suggesting there are ways to enable behavioral change to happen over night?

  6. Cezary says:

    there some new ways to make behavioral change quick, pleasant and easy

    hard to summarize this knowledge in this short blog note, let’s say that using proper mind-body states, suggestibility, neuro-cortex synesthesia, submodalities and such, you can easily reprogram your mind to associate new/old behaviours with positive/negative reinforcements, which brings automatic and natural change and adjust your beliefs to support that change

    human mind learns quick, not slow, supposing you have proper tools

    maybe this isn’t overnight job, but it’s simpler and quicker that trying to struggle with changing habbits using old ways

  7. I would agree with this. But as with anything else… it’s a case by case basis.

  8. cezary says:

    …and as anything else (and bodyimprovements advices as well) can be simplified and delivered as knowledge and toolset and set of practices that can be beneficial for many people in order to have positive changes
    we are working on something like this here in poland (some kind of audiosets to reimprint behaviours in quick and easy manner) one of use we thoughtof is some kind of “improve your dieting habits”, so may you ll be interested

  9. Jack says:

    slow carb diet…

    After reading your article I am left with the feeling that there is more to this topic than I originally thought….

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