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I finished reading a book on nutrition called Burn, new research blows the lid off how we really burn calories, stay healthy, and lose weight by Herman Pozner, PhD. Once again, my idea of a healthy diet and good weight maintenance got turned on it’s head.

Let me back up a bit.

When I first got involved in the fitness industry, our idea of a healthy diet and weight loss plan went something like this:

  • Eat a high carbohydrate diet consisting of breads, grains, pasta, rice, beans and other vegetables
  • Fairly high protein intake. Supplement your diet with one or two protein shakes every day, especially after a workout.
  • Keep fat intake very low, especially saturated fats.
  • Eat four to six small meals throughout the day.
  • Weight loss was a matter of less calories coming in than going out. You can manipulate that by increasing exercise, eating fewer calories, or a combination of both.

Does it sound familiar? That is what I recommended to my clients. To a certain degree, it worked. Over half of my client’s were successful following this plan. However, many of my clients were not very successful. No matter how hard they tried, they could not lose weight. These same clients struggled with energy to get through the day and were ravenous all the time. I just could not seem to be able to help them very much.

Next up for me was the low carb movement. I had heard about it ever since I was a trainer because Dr. Atkins was the front man in getting out that message. He started his low carb journey back in the 1960’s, but his movement gained traction in the early 1980’s. I never gave it any serious thought back then because, well…heart attack right? Anyhoo, I decided to take a closer look at the low carb approach about 15 years ago. I was inspired to dive into the low carb diet a bit from a book a client gave me written by Tim Ferris. It was called The 4-hour body. Tim Ferris is not a fitness guru. He is more of a generalist and a lifestyle guru, as his profile says. In any event, his book did get me thinking that I need to see for myself if the low carb way had any merit, so I chose to do a mini experiment on myself. I went low carb for 6 six months just to see what it was like, and I was blown away by the results. I lost 14 pounds and I maintained my strength…a good sign I kept my muscle. Moreover, I was more defined in my muscle than I have ever been when I went on a low calorie diet to lose fat, and I was never hungry. I did some simple calculations and realized that I was eating about 800 calories less a day that when I was on a higher carbohydrate diet. Once again, without feeling hungry.

I read many books on the low carb diet that I still think has value and merit. The Primal Blueprint by Mark Sisson, Good Calories/Bad Calories as well as Why We Get Fat: and What To do About It by Gary Taubes, along with other low carb authors. I was hooked, and I started guiding my clients to a more Paleo/low carb style of eating. The success of my clients from this advice was better. Much better. As an example, one client I have been training for several years decided to try the low carb approach and he saw rapid weight loss for the next six months. He lost over forty pounds! Here’s the crazy thing: he looked like he did not need to lose that much fat to begin with. He looked strong and fit before he started. Both of us were surprised that he had that much to lose! Having said that, I still did not have a 100% success rate. It was much better, but I still have clients to this day who struggle with losing fat and maintaining a leaner body.

The basic premise of the low carb approach to weight loss and health has to do with hormones. Insulin is known to drive glucose out of the bloodstream and into the glycogen stores of the muscles, and any remaining blood glucose into the fat cells. Concurrently, insulin also prevents the body from tapping into the fat stores for fuel. Thus, as long as circulating insulin levels are high, the body tends to run on glucose only. One of the main things that drives chronic high insulin levels are high carbohydrate diets. Frequent eating and eating highly processed foods also lead to high insulin levels (so much for the six small meals a day for fat loss theory). Thus, the theory is that if one eats a low carb diet, it is much easier to keep insulin levels down so the body can burn fat, thus making it easier to stay lean without having to focus on counting calories.

Makes sense, right? Problem solved, or so I thought.

Until I read Burn. The author, Herman Pozner, PhD, is a researcher studying metabolism and he spent some time living with the Hazda tribe in Tanzania. He took various measurements to figure out their basic metabolic rates, activity levels, food intake, lifestyle and so on. The Hazda are among the few remaining indigenous tribes that are about as untouched by modern civilization today as any group can be. Unsurprisingly, they rarely suffer from modern diseases such as cancer, diabetes, obesity and dental caries. So what was his big block buster news?

Three things about his research stood out to me. The first one was how set our basal metabolic rate is. He found that, on average, the Hazda men would burn about 3,000 calories a day, and women about 2,000 calories a day, which is notably higher than what most exercise physiologists would say. It is assumed that men burn about 2,000 calories a day and women around1,500 calories a day, give or take. The second thing that stood out was how hunting for food was central to their day. They would spend hours each day picking for tubers and other root vegetables as well as walk for miles hunting and gathering honey. The third thing that made an impression on me was that their typical diet was very carbohydrate rich, and according to the low carb hypothesis they would have insulin sensitivity issues, but they do not. They are very healthy.

Back closer to home, the debate between the low carb camp who believes that hormones drive obesity and those professionals that believe that fat gain is a simply a matter of more calories coming than is going out no matter what the calorie source is rages on. Obesity researcher Stephen J. Guyenet in his book The Hungry Brain, for example, is very clear that it is not hormones that drive obesity. It has far more to do with the brain and how it is wired to eat from a time long before our Paleo ancestors for survival, and that modern foods short circuit this wiring to make us overeat. His overall advice is to eat a more bland diet so the brain is not tempted to overeat. Sounds fun, doesn’t it?

So where does that leave us? I realized several years ago that I simply cannot be dogmatic about my approach to a healthy diet. New science keeps coming out challenging or confirming past nutrition advice. Furthermore, I always find a kernel of truth, or more specifically a piece of wisdom that I can incorporate into my own diet or advice that may be more specific for a client whenever I read another nutrition author or research study.

Having said that, there are general nutrition guidelines that we can all adopt no matter what we like to follow, be it low carb, basic calorie counting, and yes, some pointers for the vegans as well.

I’ll write about that in my next post.


Gregg Hoffman