Wednesday, May 11, 2011

How sweet it is.

(Acknowledgement: This post was greatly improved by the input of nutrition-guru, Tess McEnulty. Thanks, Tess!)

Go to any bookstore, pick up any lifestyle magazine, or watch pretty much any talk show, and you will get advice on how to eat. Most of this advice mimics the USDAs new food pyramid and nutrition guidelines. We are all familiar with this advice: eat fewer calories, avoid foods that are high in cholesterol or fat (especially saturated or trans fats), and eat lots of fruits, vegetables, whole grains, and lean meats and dairy.

Perhaps you have also heard that unprocessed foods are better than their processed counterparts. Oranges, for example, are better for you than orange juice according to Michael Pollan’s In Defense of Food. Local, organic, and seasonal are also associated with healthy foods. These fruits and vegetables have to make it to consumers quickly or they spoil. That extra freshness likely translates to higher nutrition.

Despite all of this information, we still have an increasingly obese population. Certainly some people simply choose to eat poorly. But we all have friends (or even have experienced this ourselves) who seem to follow all the rules and still have trouble losing weight. In recent years, several theories have come out suggesting that perhaps our idea of what constitutes a healthy diet is actually flawed. Three notable people at the center of these investigations are Gary Taubes, Robert Lustig, and Loren Cordain. In many ways, their conclusions are similar, but each one has focused on a different aspect of why and how we gain and lose weight.

Forget about calories. And fat. Oh, and cholesterol too.

Science writer, Gary Taubes, has done extensive research into the scientific case linking the consumption of fatty foods and cholesterol to obesity and heart disease. As reported in his 700-page book, Good Calories, Bad Calories, Taubes found the so-called evidence unconvincing. Instead, he learned that our bodies’ ability to regulate blood sugar seems to hold the key to keeping us healthy. The connection between fat storage and insulin response is better at explaining why certain cultures are healthier than others. Consuming refined carbs and sugars, which play a large role in our Western diet, triggers an insulin response and ultimately lead to metabolic diseases such as Type 2 diabetes and obesity.

When it comes to losing weight, Taubes dismisses the notion of calorie counting. We often think of weight loss, or more specifically fat loss, as an equation. How much you weigh equals the calories you take in minus the calories you burn through regular activity or exercise. If that were true, simply reducing calorie intake or increasing calorie burn should lead directly to fat loss. However, if your body chooses whether to store or burn fat based on hormones and insulin levels, then reducing calories won’t necessarily allow you to lose more fat. The key is to keep your insulin levels low, so that your body responds more sensitively to insulin and is willing to give up the fat.

The best way to keep your insulin levels low is by vastly reducing your intake of refined carbs and sugars. Eat as much as you want, but eat the right foods: plenty of vegetables (especially the green leafy kind), quality animal proteins, nuts, and nut butters. Legumes, whole dairy, or whole grains are probably fine for most people, especially those at their target weights, but they may inhibit weight loss.

A recent article in Men’s Journal (my dad sent me a copy), covered Taubes’ diet guidelines in a bit more detail than I will here. They offer recipes, a sample week-long meal plan, and this Taubes-style food pyramid.

Endocrinologist and professor, Robert Lustig, is also concerned about the effects of insulin resistance on weight and health. He is focusing mainly on the effects of fructose, the type of sugar found naturally in fruit and honey and in the form of high fructose corn syrup (HFCS), which now appears in many processed foods from soda to bread.

Fructose is processed in the liver, which Lustig believes can only handle so much fructose at one time. When we eat fruit, the fiber it contains helps the liver process the fructose – not the case when we consume fructose in other forms such as soda and other sweetened beverages. In a popular YouTube video, Lustig explains that over-consumption of fructose can lead to liver disease, metabolic syndrome, and eventually, obesity and it’s accompanying problems. Unlike the average 15g of fructose that most people would get from daily consumption of fruits and vegetables, today’s teens average 72g per day from other sources like soda and junk food.

So yummy, a cave man could eat it.

As I mentioned in my previous post, Loren Cordain is one of the main proponents of The Paleo Diet. The philosophy behind Paleo is to consume only those foods that we have been eating since before the agricultural revolution. The foods we survived on as hunter-gatherers are the foods we evolved to consume, so our bodies are better able to tolerate them and utilize their nutrients. The Paleo Diet differs a bit from the Taubes-Lustig paradigm. People following the Paleo diet do not eat grains, dairy, or legumes. The refined carbs and sugars that Taubes and Lustig are warning us about are certainly excluded in this diet, but starchy vegetables and fruit are considered okay in moderation.

There is now a great deal of work looking into why exactly the classic hunter-gatherer foods are healthy while many newer ones are not. Research suggests that some agriculture-based foods contain so-called anti-nutrients. These are natural defense mechanisms that certain plants employ to keep from being eaten. Despite our cleverness at making these foods edible, they may actually lead to many chronic health problems such as auto-immune disorders, asthma, and more.

Switching to a Paleo diet may sound rather daunting especially compared to the typical American diet. It took me about a year to transition from pizza and soda to a veggie-centric diet. Slowly but surely, though, anyone can make the switch. Even with all the changes I have made, this trio of nutrition experts has caused me to wonder just how healthy my diet really is.

How do I stack up?

Based on the USDA guidelines, I eat a healthy diet. I consume a lot of vegetables, cook most of my meals, and haven’t eaten at a fast food restaurant or ordered a restaurant burger in years. But how much sugar is in my “healthy” diet?

The following table shows what foods I typically eat for breakfast, lunch and dinner, plus snacks and dessert. While some of my food choices would certainly be Lustig-approved (my English muffin plus peanut butter has a mere 1.5g of sugar), nearly all my snack choices have 13-19g of sugar despite being healthy-sounding foods. If I chose the lowest sugar option for each meal and had only one snack, my total sugar intake for the day would still be close to 30g. With the highest-sugar options, my daily intake of sugar would be nearly 120g!

Unfortunately, there is no USDA daily recommended intake of sugar. The American Heart Association does have a recommendation though: 20g of added sugar per day for women and 36g for men. Even my lowest sugar options would be too high by this measure. And although many of my sugars are from fruit (so not added sugars), one granola bar is basically my whole sugar allotment for the day.

Another way of visualizing sugar is by comparing it to things we perceive as being sweet treats. The website, Sugar Stacks, goes one step further by showing popular foods next to the equivalent number of little white sugar cubes. My daily sugar intake is on par with a liter bottle of soda, 2 Rockstar energy drinks, or 2-3 bags of Skittles. On the one hand, that seems like a lot sugar for natural healthy foods. On the other hand, a college freshman who consumes a couple of energy drinks has ingested as much sugar as I eat in a whole day! Either way you look at it, we are getting a lot of sugar.

Knowledge is power.

My sugar intake is lower than the average American, who apparently consumes a staggering 90 pounds of sugar each year (that’s >100g every single day), but it may still be too high. Now that I know, I can make better choices. For example, topping my salad with 2T of fresh blueberries rather than 1.5T of raisins would reduce my sugar intake by 8.6g. Sticking with black coffee or tea instead of a latte reduces it by 17g. And eating my tuna salad over mixed greens with a little balsamic vinegar rather than as a sandwich saves me another 5.4g - and I get my greens!

Snacking seems to be my worst area. Here are some easy snacking alternatives that would really make a difference in my diet. Rather than a granola bar or fruit (13-19g of sugar), I could eat:

  • 2T hummus and 1 chopped carrot, 5g
  • Trader Joe’s Roasted seaweed snack, 0g
  • 1/2 English muffin with 1T peanut butter, 1.5g
  • 1/4 cup raw almonds, walnuts, or cashews, 0-2g

Cordain, Taubes, and Lustig offer a glimpse into a real-food loving future. Imagine, you can eat all you want and not get fat. You can enjoy a big juicy steak, cashews, avocados, even scrambled eggs and bacon. You can stop worrying about cholesterol and calories. All you have to do is give up the sugar. Sounds like a pretty sweet deal.

Additional resources:
- Gary Taubes recently wrote an article in The New York Times about Lustig and his work
- The recipes for my dinner options have been featured in previous posts: 15-minute fish and hearty black bean stew

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