The skinny on fat cells

Eating fatty foods has a “shocking” effect.

Gregory Nemec

Gregory Nemec

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If trends hold, more than half the world’s adults will be overweight or obese by 2030. In a study of mice fed a high-fat diet, Matthew Rodeheffer, an assistant professor of comparative medicine, and his colleagues discovered some reasons why this trend is so hard to turn around.

Fat, it turns out, sings an irresistible song to a group of cells known as adipocyte precursors (APs): it triggers the machinery that transforms APs into mature adipocytes—fat cells.

Ordinarily, there’s a control mechanism, says Rodeheffer: “The body is forming fat cells constantly. There’s a low and continual turnover of about ten percent per year, and the total number of adipocytes is tightly regulated.” But feasting on fat upsets the control mechanism, and does so faster than anyone had suspected.

The researchers found that the number of APs doubled in the first week the mice were on the high-fat diet, and, even after accounting for turnover, there was a rapid 15 to 20 percent increase in the number of fat cells ready to fill with lipids. “The speed with which this occurred was shocking,” says Rodeheffer, whose report appeared in the March 2 issue of Nature Cell Biology. So was the finding that the increase persisted. “The body defended the higher level of fat cells and somehow changed the homeostatic set point.”

Weight loss was possible, but resulted from shrinking fat cells, not eliminating them. “Even short binges can lead to irreversible changes,” adds Rodeheffer.


  • Cyndi Chen
    Cyndi Chen, 3:04pm June 23 2015 | Ico flag Flag as inappropriate

    Curious--is this true of all fatty foods, or just saturated fatty foods? I know nothing about how fat interacts with adipocytes, so I'm curious about this "irresistible song"!

  • arthur rosenzweig
    arthur rosenzweig, 1:22pm July 01 2015 | Ico flag Flag as inappropriate

    Without reference to the carbs in this fat diet, this report is
    doctors' propaganda. My own experience-at age 86- with the keto diet, I couldn't gain weight and I kept normal blood pressure and perfect health with some strength exercise. Only on the keto diet do you have the incentive to learn all the sugars in your lifelong healthy diet. Obesity and diabetes are not from fat, you know.

  • Rahul Islam
    Rahul Islam, 1:36pm July 03 2015 | Ico flag Flag as inappropriate

    This may be true if you suffered from childhood obesity.
    But let me remind you all that the number of fat cells are established during childhood and puberty. In adulthood obesity does not increase the number of fat cells unless you exceed over 30KG total body fat. Only then fat cell hyperplasia occurs.

    “Early onset obesity is associated with increase adipose cell number while adult obesity is associated with normal cell number. There are two phases of life in which growth of adipose cells are likely to develop: very early, within the first few years of life and between the ages of 9-13 years of age. Those who become very obese early in life are the ones who have nearly normal cell size but have the greatest increase in cell number; whereas those with onset of obesity between 9-13 have more change in cell size than cell number.” Salans LB, Cushman SW, Weisman RE, Studies of human adipose tissue.

    My experience proves that this is not the case. I was skinny during childhood a normal weight during adolescence years. From 19-23 I was a few kilos overweight. At 23 my heighest weight was 90KG about 198 lbs at 5"10.5 BMI 28.

    I dropped to 62 KG BMI 19.35 in February 10 2014 and have since then remained exactly the same weight for almsot 17 months now without counting calories. The fact that body has not desire to increase the weight back on and I don't have increased hunger pangs is an evidence that there are no excess fat cells.

    And during my college-uni time I ate a lot of potato crisps, junk food, sugary drinks, etc. My weight gain was a slow one at 1-2KG per year. It was enough to add over 10KG in 5 years. But if the weight gain is slow there's no reason for fat cells to multiply irrespective of your macro nutrients.

    All I did was give up junk food, sugary drinks, potato crisps, stopped snacking and stopped self-rewarding. The set-point weight was never affected. My childhood weight set point was indeed an indicator that adulthood weight was going to be low as well and it was!

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