Biting into too many “apples” the beginning of obesity ?

frutose tying leptin upHuman woes officially began when Eve persuaded Adam, to take a bite from the fruit of the tree of knowledge.

Research published by the American Physiological Society suggest that biting into fruit sugar (fructose), is the beginning of fatness.

Leptin the regulator

The body’s energy requirements are typically tightly regulated in NORMAL people. A key player in keeping the body properly fuelled up, is leptin.

Leptin keeps tabs on the fat fuel supply and initiates appropriate responses when fat levels change.

  • If the body’s fat levels dwindle, leptin levels drop – kick-starting a massive drive to eat i.e. the hunger response
  • If the body’s fat levels rise, leptin levels rise too – launching a laid-back, engorged sense of satisfaction i.e. the appetite suppression response.

In the obese, the leptin regulator is shot. The excess fat, spikes the leptin levels into the stratosphere, but the message falls on deaf ears. Despite adequate fat supplies, eating never stops. Excess calories in, ultimately translates to excess fat.

Fat people are typically both leptin and insulin resistant.

Fructose in the dock

As obesity rates have climbed, science has scrambled to provide explanations.

Fructose, more specifically, high-fructose corn syrup frequently appears on the fat charge sheet. But, up until now, it has been difficult to make the charges against fructose stick.

Fructose effect is slow

Researchers from the University of Florida set out to unravel fructose’s role in obesity.

They began with two groups of rats. One group ate lots of fructose, the others went fructose-free. The rats looked and acted pretty much the same for the first 6 months. There were no differences in the amount of food consumed, the animal’s body weight or fat levels.

Blood work showed few differences. Leptin, glucose, cholesterol and insulin levels were the same. Triglyceride levels were a little higher in the fructose fed group – a clue that all was not quite right.

Fructose gets leptin tied up in knots

But something sinister underpinned the apparent sameness.

When the researchers tested the rats for leptin resistance, by giving the animals a shot of leptin, the fructose rats failed the test. Fructose free rats stopped eating, following the leptin shot, but the fructose eating rats just kept munching.

Fructose doesn’t work alone

The rats in the study were leptin resistant, but they hadn’t ballooned into FAT RATS, yet.

But turning them into fat rats was a synch.

All the researchers did was change the grub being served to the rats. The rats were offered foods that were a little more palatable i.e. treats high in sugar/salt and fat at the same time, than normal rat kibble.

When fed the rat equivalent of crisps and ice cream – all resistance crumbled. The leptin resistant animals tucked in and subsequently exploded in size.

Cut the fructose

Most dieting advice admonishes cutting sugars, while encouraging fruit consumption. This advice may not be specific enough. “Sugar” is clearly more complicated. Fructose pops up in high-fructose corn syrup, table sugar, honey, agave syrup and FRUIT.

The secret to keeping the pounds at bay – limit your fructose intake and stay away from those highly addictive munchies full of fat and sugar.

Fructose-Induced Leptin Resistance Exacerbates Weight Gain in Response to Subsequent High Fat Feeding. AJP Regulatory Integrative and Comparative Physiology (2008) 295(5): R1370-R1375.   Alexandra Shapiro, Wei Mu, Carlos Roncal, Kit-Yan Cheng, Richard J. Johnson,and Philip J. Scarpace  

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Further reading

fat sippy cup drinking juice fructose teasing insulin running on coke
Juicing up is fattening up A spoonful of fructose makes the fat cells full Choosing water to quench your thirst  is a no brainer when counting calories

The 7 Big Spoons™…. are master switches that turn health on.

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Balance Eicosanoids Rein in insulin Dial down stress Sleep ! Increase Vit D Culivate microflora Think champion

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