December 29, 2020
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There’s a lot of confusion about carbohydrates (or carbs for short).
Even leading nutritional experts disagree on the right answers to these questions. But the truth is that there is no ‘right’ answer: it all depends on your unique metabolism.
We sat down with leading nutrition expert Christopher Gardner, Ph.D., Professor of Medicine at Stanford University, to bust some common myths and discover the truth about carbs.
Carbohydrates are one of the three major nutrients found in foods (the others are fat and protein) and are made up of various arrangements of simple sugar molecules like glucose and fructose.
Some people say that carbs are not essential, because we can make glucose in our bodies (via a process known as gluconeogenesis). While this is technically true, it misses the much broader role that carbohydrate-containing foods play in nutrition and health.
Carbohydrates are found in a wide range of foods, many of which are great for our overall health and support a healthy and happy gut microbiome.
Many carbohydrate-containing foods form part of a healthy diet, such as fruits, nuts, whole grains. These foods also contain other important nutrients, including vitamins, minerals, and phytochemicals, which are important for health.
“Foods that are good sources of carbs are essential to a healthy diet,” explains Christopher.
Some people view all types of carbs and carb-containing foods as essentially the same, arguing that you can directly compare a banana, say, to six spoons of sugar. But that’s simply not true.
How we prepare and cook food can have an impact on how our bodies break down and absorb the nutrients it contains. This is because foods have complex structures, known as the food matrix.
Processing or cooking can change those structures to make carbs more accessible by removing the fiber and other nutrients or through the addition of sugar.
Research shows that we have been eating roughly the same amount of carbohydrates, fat, and protein in our diets for the last 20 years. However, the type of carbohydrate that we are consuming has changed.
Low-quality carbs from processed foods high in added sugars represent more than 40% of our daily calories, while high-quality carbs from whole grains, fruits, and vegetables make up less than 10% of our calories.
The good news is that this gives us a lot of room for replacing low-quality carbs in our diet with high-quality carbs or healthy fats (like nuts, avocados, or olive oil), depending on the foods that work best for our individual biology.
Eating whole foods that include high-quality carbs rather than cutting them out completely is likely to be less restrictive, more varied, and more sustainable in the long run.
“We don’t just eat nutrients, we eat food, and food provides pleasure, culture, taste, and enjoyment,” Christopher says.
There’s a lot of talk about low-carb diets for weight loss, but the evidence shows that they don’t work for everyone.
The DIETFITS study, led by Christopher and his team, showed that there was no difference in how much weight people lost on either a low-fat or low-carb diet.
While the 609 participants losing an impressive 6500lbs between them, there was massive variation in weight loss between people on the same diet.
The take-home message from this study is that no one diet is successful for everybody, as we all respond differently to the foods we eat.
Adding to this, our PREDICT study shows that we all respond differently to the carbs in our food.
Some people believe that following a very low-carb or ketogenic (keto) diet is a good way to control blood sugar levels, especially for people with type 2 diabetes or pre-diabetes.
At the moment, there isn’t enough evidence to show that this is true, but Christopher and his team at Stanford are trying to find out.
They’re running a study called Keto-Med, comparing the keto diet with a healthy Mediterranean diet to see which diet is better for helping to control blood sugar levels.
They’re also looking at other measures like weight, blood pressure, blood fat levels, and inflammation, as well as how strictly people are able to stick to their allocated diet.
“If you want to eat a lower-carb diet I am totally in favor of getting rid of as much as possible or all of the low-quality carbs,” Christopher says. “If you did that, could you just replace them with high-quality carbs? Or with more fat from nuts, seeds, avocados, and fatty fish?”
Christopher highlights a few simple rules when it comes to choosing carbs.
First, eat fewer added sugars and refined carbs and limit your intake of highly processed foods.
Include whole grains, tasty vegetables, and legumes, prepared in interesting and delicious ways. If you aren’t sure where to start, check out our blog post for some tips on how to get more plants on your plate.
You should also aim for a diverse diet, rather than eating the same foods all the time.
“You should be eating a healthy diet and then build on that with personalization. Everybody should be eating more vegetables and more whole foods,” Christopher explains.
“Everybody should be eating less added sugar and refined grains, and that’s going to be 50% of the issues that people can clean up in their diet. After that, then there’s a wealth of taste and personalization open to you.”
At ZOE, we believe that understanding how your body works is key to picking the right foods for you.
Our unique at-home test kit lets you discover your metabolic responses to carbohydrates and fats, along with personalized advice about the food choices that will work with your metabolism and microbiome to help you reach your healthiest weight and improve your gut health.