A team of 17
internationally recognized scientists published a paper supported by more than
169 journal references, proposing that the current obesity epidemic is not
caused just by taking in too many calories (Am J Clin Nutr, September 13, 2021).
They believe that obesity is caused primarily by hormonal changes brought on by
eating refined carbohydrates and sugar-added foods. These foods cause a high
rise in blood sugar that markedly:
• increases insulin secretion that makes you hungrier (N Engl J
Med, 1971;285(8):443-9), and
• decreases glucagon secretion that functions to make you feel full, so you
keep on eating (Trends Endocrinol Metab, 2018;29(5):289-99).
Insulin also causes changes in metabolism that signal fat cells to store more
fat (Obesity, 2020;28(11):2098-106). These studies do not
recommend restricting all carbohydrates, just those that cause high rises in
blood sugar (Science, May 7. 2021).
What Are Unrefined and Refined Carbohydrates?
Unrefined carbohydrates are parts of plants that have not been stripped of
their other outer coatings, ground up and otherwise changed before you eat
them: whole fruits, vegetables, un-ground
whole grains, beans, nuts and other seeds. Refined carbohydrates are plant
parts that have had basic components removed or have been ground into flour:
all extracted sugars, bakery products, pastas, most dry breakfast cereals and
so forth. Fruits can contain a lot of sugar, but they are considered unrefined
because they have soluble fiber and antioxidants that markedly reduce the rise
in blood sugar when you eat them (Exp Ther Med, Aug, 2016;12(2):
1232–1242)..
You Need Carbohydrates
Carbohydrates are usually the main source of energy for our bodies to function,
while protein provides amino acids to grow and repair our cells. Carbohydrates
are sugars in singles and combinations of up to millions of sugars bound
together. Humans can absorb only single sugars. Most unrefined carbohydrates
contain many sugars bound together, and we lack the intestinal enzymes to break
them down. Most of the carbohydrates in vegetables, unground whole grains,
beans, nuts and other seeds cannot be absorbed from the upper intestinal tract
so they pass all the way to the colon where bacteria do have the enzymes to
ferment them and break them down to short
chain fatty acids or SCFAs (Proc Nutr Soc, 2015;74:13-22). These
byproducts of fermentation by bacteria in the colon cause good bacteria to grow
in the colon, which reduce inflammation
that contributes to heart attacks, diabetes, cancer, and obesity (World J
Gastroenterol, 2011;17(12):1519-1528). They also lower high blood
pressure, high blood sugar, and high cholesterol.
Evidence Linking Refined Carbohydrates and
Obesity
Overweight people who eat mostly whole foods rather than processed foods can
lose weight without counting calories or restricting portion sizes:
• A study from Stanford showed that restricting processed foods, particularly
added sugars and other refined carbohydrates, is more important for weight loss
than going low-carb or low-fat (JAMA, Feb 18, 2018;319(7):667-679).
• A study from the University of Aberdeen showed that eating whole plants
rather than refined plant foods, such as those made from flour or with added
sugars, results in far more healthful intestinal bacteria than a diet with high
protein or added amino acids (European Journal of Nutrition,
February 20, 2018:1-12).
My Recommendations
• What you eat may be far more important than how much you eat.
• Obesity increases risk for heart attacks, cancers, diabetes and premature
death.
• Counting calories or trying to limit portion sizes have been repeatedly shown
to fail to control weight in the long run.
• Studies on colon bacteria are showing that eating lots of unrefined
carbohydrates from plants and avoiding refined carbohydrates, such as
sugar-added foods and drinks and foods made from flour, can help people lose
weight and keep it off.
• I recommend eating plenty of vegetables, beans, whole grains, nuts and other
seeds, and whole fruits.
