Nutritionist says science backs importance of carbohydrates for sports formulations

28-May-2015 - Last updated on 29-May-2015 at 15:35 GMT

Has the low carb craze finally been consigned to the dustbin of history? Nutritionist Susan Kleiner, PhD thinks so, and it’s high time, she said.

Kleiner is a practicing nutritionist and is also developing her own sports nutrition company called Vynna LLC that will focus on women-specific dietary supplement and functional food formulations. Kleiner’s goal with the company (disclaimer: the company’s launch product is based on Vitargo, a proprietary carbohydrate molecule) is to develop the science behind proper sports nutrition for women, which up to now has been based on what has been shown to work for men, only less to account for smaller body sizes. She said that’s a pure assumption—a potential myth. On the way to dispelling that myth she has tackled others, such as the efficacy of low-carb diets and the usefulness of basing nutrition decisions on a food or supplement’s GI index alone.

Carbs back in vogue

“I’m noticing a shift on the messaging. To me it feels as if its happening all at once. Within the sports world the message is no longer so heavy on the ketogenic diet, the idea that you really do best with extremely low carbs,” Kleiner told NutraIngredients-USA.

Kleiner said much of the excitement surrounding the low-carb craze was driven by marketing. From her point of view, there was little if any data backing the claims. A case made for a certain nutritional mode—that our ancestors had access to certain foods and not others, skewing the table when it comes to what we are best adapted to eat, for example—might seem to make sense at first glance. But without hard data, you can’t know if its true. And testimonials aren’t data, she said.

“My personal message is and our message as a company is to demand science and to understand what that means to demand science. Just because a company says they are science based does not mean they have real science on their product, their diet or whatever,” Kleiner said.

A number of influential trainers—names such as Dean Somerset, Bret Contreras and Dr Brad Schonfeld—are coming forward demanding science backing for the exercise regimens and nutritional products they recommend to their clients, Kleiner said.

“These are influencers who are beginning also to continue this paradigm of demand science before you act. Once you get to that point it doesn’t matter how many claims you make about a diet or how many champions or beauty queens you march out in front of the public. Science is not an anecdotal story; it is peer-reviewed and published in a peer-reviewed journal. When you present the evidence as it stands there simply is no data to say that a very low carbohydrate or a ketogenic diet will enhance performance,” she said.

Kleiner said she has seen clients in her practice who have gotten their bodies badly out of balance trying to train without sufficient carbohydrate intake. It’s an especially difficult burden for women to bear, as their reproductive systems are biochemically so much more complex than are men’s. There’s more to go wrong, and it’s harder to put it right, she said.

Kleiner said in particular that adequate carbohydrate pre- and post-exercise can be a key element to keeping athletes healthy. It’s well known that heavy training might be good for your muscles and cardiovascular system, but it’s not necessarily helpful for your immune response.

“There is some quite fascinating data about carbohydrate in particular and the window of immune suppression post exercise. There was some research done a while ago about what you could supplement with to minimize that window. The factor that made the biggest difference was having enough carbohydrate in your diet,” Kleiner said.

Bye, bye to the myth of GI

Kleiner is also working to dispel myths around the notion that a food’s glycemic index is the be-all and end-all when it comes to assessing a food or supplement’s blood sugar performance.

“There are three myths surrounding that. One is that when people think of the Glycemic Index they think it measures how fast the carbohydrates are digested and absorbed. GI is just a measure of the total rise in blood sugar over time,” Kleiner said. It does not measure insulin response, or how fast the sugar is removed from the blood stream, she said.

The second myth concerns the structure of the carbohydrate itself. Simple carbs are fast and complex carbs are slow, right? Wrong, Kleiner said. Carbohydrates enter the blood stream at similar rates, regardless of their structure. A complex carbohydrate may stimulate a more rapid insulin response, thus being removed from the blood stream more quickly and efficiently and getting into cells, including muscle cells, earlier. It doesn’t show that rapid and high blood sugar spike, thus appearing to be “slower,” while actually fueling the body more rapidly, Kleiner said. (A caveat: Measuring blood sugar levels for diabetics is a separate issue).

Kleiner said a third myth then becomes that a food or supplement’s GI index is a useful tool in deciding whether the products is healthy.

“Should you choose all your foods and supplements based on that? No. The concept has been hijacked by the processed food industry that says, buy our engineered food or our highly processed bar because of its GI index. See? It’s good for you,” Kleiner said.

“I’m not really anti or for GI. It’s just that the claims people make about it don’t match the science. It’s really an abstract measure. You need to know more details about the food or supplement.

"My entire career has been about helping people make smart choices. People will research the purchase of a dishwasher, yet they will buy and put it into their bodies with no better information than the guy lifting weights next to them at the gym said this stuff is great. I want people to put their money into food first and only supplement when they must and then to use their funds carefully,” Kleiner said.

Immune health forum

Susan Kleiner, PhD will participate in this month’s NutraIngredients-USA Immune Health Forum, an online discussion set to air on June 30. The forum will also inlcude Philip Calder, PhD of the Univeristy of Southampton in the UK, Dr Refaat Hegazi, medical director of Abbott Nutrition and Ivan Wasserman, administrative partner of the Washington, DC office of the Manatt law firm. To register for the event, click here.