Having addressed the much-hyped protein debate, lets now move our attention to Carbohydrates, another highly controversial issue today. Many mainstream schools of thought consider carbs as the main culprit when it comes to obesity and diabetes and advocate strictly controlling the intake of carbs in our diet. Several diets like Atkins, popular with many folks running after weight loss, advocate severe curtailment of carbs in our diet.
What’s the reality? Are carbs really bad for us? What role do they play in our nutrition and health? There are some of the questions that I intend to address in this blog.
Let’s start by examining some simple facts about carbs.
Carbohydrates – some basic facts
Carbohydrates is one of the 3 macro nutrients (the other two being protein and fat) present in our food.
The 3 main types of carbohydrates are sugar, starch, and fiber. They’re simple or complex, depending on their chemical structure.
While simple carbohydrates like fruits digest quickly and release their energy fast, complex carbohydrates like pulses, sweet potato, tapioca, yam and whole grains digest slowly and release their energy gradually.
Fiber is an Indigestible carbohydrate, that is essential for intestinal health. It assists in regulating the body’s use of sugars and keeps hunger and blood sugar in check. Fiber also changes the way our body digests and absorbs cholesterol.
Fiber is also food for the gut bacteria and thus helps determine gut bacterial composition and gut health.
Fiber plays an important role in cell proliferation and inflammation in the gut and has been linked to lower rates of colorectal cancer.
Fiber comes only from eating whole plants!
How are carbohydrates used by our body?
Carbohydrates are metabolized into simple sugars like glucose (blood sugar) by our digestive system.
They are used as the main energy source by all body tissues. Brain, kidney, muscle and heart functions depend primarily on certain types of carbohydrates.
The energy produced by carbohydrates is 4 calories per gram.
Source of carbohydrates
The food sources for carbohydrates are fruits, vegetables, nuts, grains, seeds, and legumes.
Refined Carbohydrates
Refined carbohydrates, extracted from plant parts, are forms of sugars and starches that don’t exist in nature.
Refined carbohydrates raise insulin levels and promote obesity when combined with fat, but carbohydrates in whole foods have the opposite effect.
An illustration of refined vs whole carbs are whole grains (e.g. unpolished red rice) vs refined grains (e.g. polished white rice)
Whole Grains are seeds of plants and contain.
Bran: the outer layer of the seed
Endosperm: the starchy energy supply for the embryo, which makes up the bulk of the see
Germ: the embryo of the seed, capable of sprouting into a new plant
But refined grains typically contain only the endosperm, as the bran and germ are lost in the polishing process. Thus, refined grains do not contain the nutrients present in the bran and germ and lose most of the fiber.
Refined grains, such as white rice and white flour, lose up to 80% of their nutrients and fiber
Refined grains have harmful effect on health and combined with fats are a cause of diabetes and obesity!
Do Carbohydrates cause diabetes?
It’s a common misconception that carbohydrates cause diabetes.
A perception created to hide the reality that its the fat in our diet, saturated fat derived from animal sources and transfats derived from processed plant foods, that are the real culprit!
The graph on the left clearly shows the reality. US with the highest fats and lowest carbs has the highest diabetes vs Japan with the highest carbs and lowest fats, has the lowest diabetes
In 1970s China Study, fat was ~8-10%, protein ~5-10% and carbohydrates 80+%. Diabetes was almost nil.
But post opening up China started adopting western diet habits. The result has been Carbs in their diet have been falling, and protein and fat steadily increasing.
Increase in fat and protein has come from added oils, animal foods, processed foods (with refined carbs) and sugars.
And the rising trend in diabetes is clearly visible; from 2.5% of the population in 1991 to 11.6% in 2011 and rising rapidly!
To conclude
Whole Food Plant Based (WFPB) diet naturally derives around80% of its calories from carbohydrates. Carbohydrate here are natural and include a combination of simple sugars, slightly more complex starches, and the much more complex dietary fibers.
So, evidence on the ground and all the independent scientific research clearly shows that it’s not the natural carbohydrates in plant based whole foods in our diet that we need to be worried about, but the saturated fats, trans fats and refined carbohydrates in our diet. It is the latter that cause obesity ad diabetes and several other chronic diseases.
The naturally occurring carbs in whole plants foods (fruits and vegetables, whole grains and pulses, seeds and nuts) on the other hand provide us with a vital nutrient that is critically important to our body functions and is highly beneficial to our health.
Source: T. Colin Campbell Centre for Nutrition Studies
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