Movement comes with appetite

[Guest guest]

Greetings,

This article should interest anyone concerned about nutrition and weight loss.

The findings suggest that perhaps we should rethink the

several-small-meals-per-day strategy to slimming down.

http://www.sciencedaily.com/releases/2009/12/091206184138.htm

Movement Comes With Appetite

ScienceDaily (Dec. 21, 2009) — A body that is provided with food too often gets

caught up in the maelstrom of a lack of exercise, obesity and ultimately

diabetes. The trigger is a molecular switch that is controlled by insulin, a new

study by scientists from ETH Zurich has revealed.

Eat breakfast like a king, lunch like a prince and dinner like a pauper. And

nothing in between: no snacks, no sweets, not even anything we think of as

healthy. For in order to stay healthy the body needs to fast between meals. At

least this is what nutritionists would recommend were they to translate the

results of a new study from ETH Zurich into practical terms. After all, the

research group headed by Markus Stoffel, a professor from the Institute of

Molecular Systems Biology at ETH Zurich, has discovered an important molecular

mechanism that underlies a lack of exercise and therefore obesity.

The researchers present their findings in the current issue of the journal

Nature.

Hunger makes you active

The key switch player in this is a transcription factor called Foxa2.

Transcription factors are proteins that make sure other genes are activated and

converted into proteins. Foxa2 is found in the liver, where it influences

fatburning, but also in two important neuron populations in the hypothalamus --

the region of the brain that controls the daily rhythm, sleep, intake of food

and sexual behavior. The control element for Foxa2 activity is insulin, in both

the liver and the hypothalamus.

If a person or animal ingests food, the beta cells in the pancreas release

insulin, which blocks Foxa2. When fasting, there is a lack of insulin and Foxa2

is active. In the brain, the scientists have discovered, Foxa2 assists the

formation of two proteins: MCH and orexin. These two brain messenger substances

trigger different behavior patterns: the intake of food and spontaneous

movement. If mammals are hungry, they are more alert and physically active. In

short, they hunt and look for food. " If you watch a cat or a dog before feeding

it, you can see this very clearly, " says Stoffel.

Explanation found for lack of movement

The researchers discovered a disorder in obese mice: in these animals, Foxa2 is

permanently active, regardless of whether the animals are fasting or full. This

explains a well-known but until now unaccountable phenomenon: the lack of

movement in obese people and animals.

To prove this, the researchers used a genetic trick to breed mice, in the brains

of which Foxa2 is always active, regardless of whether they have just eaten or

are fasting. These mice produce more MCH and orexin and move five times more

than normal animals, in which insulin deactivates Foxa2 after eating or which

are obese. The genetically modified mice lose fatty tissue and form larger

muscles. Their sugar and fat metabolism works flat out and their blood values

are considerably improved.

Three meals a day suffice

For Stoffel, the study clearly shows that, " The body needs fasting periods to

stay healthy. " Moreover, you should make sure you have a good body weight. He

therefore doesn't think much of eating many little meals spread out over the

day; it is better to eat less frequently but well, and leave room in between to

get hungry. After all, because insulin is released during every meal, thus

suppressing Foxa2, the motivation to do physical exercise and burn sugar and fat

visibly decreases.

Norman

Denver, CO

www.DenverFitnessJournal.com