Your hormones are part of a finely tuned system. That finetuning makes them vulnerable.

Your hormones are part of a finely tuned system. That finetuning makes them vulnerable.

you’re metabolizing a meal and that you
shouldn’t consume any more. Leptin, a hormone
produced by fat cells, also tells your
hypothalamus that you’re full by prompting
the secretion of alpha-MSH, which is another
appetite-suppressing hormone.
All this helps your body maintain a balance
between hunger and satiation. Why so many
hormones in the game? “Energy regulation is
necessary for survival, so we have many
redundant pathways in case any fail,” says
Robert Lustig, M.D., an endocrinologist at the
University of California at San Francisco.
“But we were never supposed to have so
much food so readily available, and certainly
not this much sugar.”
Are your hormones in tune? Hungry? Full?
You may not be able to trust your gut. When
you put on extra weight, you start secreting
excess leptin. “And if you secrete a lot of leptin
on a chronic basis, it should tell your brain,
‘Look, you’re putting on weight; you need to
cut back,’ ” says Dr. Fonseca. But disruptions
in leptin (mostly from too much sugar)
instead tell your brain to send out hunger signals,
even if you’ve just eaten. This can lead
to fatty liver disease and insulin resistance.
“When your insulin goes up, it blocks leptin
signaling, which means your brain thinks
you’re starving,” Dr. Lustig says. This, of
course, sets up a wicked feedback cycle as you
pack on the pounds.
Beyond losing weight, your best defense
against leptin disruption is to reduce your
sugar intake. Americans consume an average
of 22 teaspoons of sugar a day; the American
Heart Association recommends that men eat
no more than 9. And it’s not just high-fructose
corn syrup that you need to avoid; table sugar
and fruit juice can be as bad as soda. In fact,
100 percent fruit juice has 1.8 grams of fructose
per ounce, while soda has 1.7 grams per
ounce, Dr. Lustig notes.