potent way of promoting healthy leptin dynamics. This is
because carbohydrate consumption and the insulin secreted
as a result are powerful leptin boosters.^14 The corresponding
leptin surge messages the hypothalamus to ramp up the
body’s metabolic engines. This system becomes
dysregulated if there is chronic high-carbohydrate
consumption, which can promote leptin resistance. But
when combined with exercise, a weekly higher-carb
“refeed” can increase energy expenditure, recalibrate mood,
and accelerate fat loss, especially for those who’ve seen
their weight loss stall.
A refeed of 100 to 150 grams of carbs should do the
trick. This is still dramatically less than that of a person
consuming the Standard American Diet—estimates are that
the average Westerner consumes upward of 300 grams of
carbohydrates a day. This is also not an excuse to eat junk
food. These higher-carb meals should be low in fat, which,
if you recall from chapter 2, can potentiate the insulin surge
and create a temporary setting of insulin resistance. (Fat can
also prevent leptin from crossing the blood-brain barrier.)^15
Great carbs for a refeed include rice (sushi is an excellent
refeed food), starchy vegetables like potatoes, or your
favorite higher-sugar fruit.
Leptin also plays an important role in cognitive function,
which is why keeping it within the normal range (i.e., by not
lowering it with prolonged low-calorie dieting or poor sleep,
and by topping it off with periodic refeeds) is critical. While