Why Diet Foods Do Not Satiate or Satisfy Us, and We Gain Weight While Dieting

From an evolutionary perspective, sweet taste means sugar and dieting may backfire, leading us to eat more until the body meets its energy needs.

Evolution has trained human brain to expect energy or calories from sweet-tasting foods and that is why low-calorie cookies or diet drinks do not satisfy us, suggests a research from the University of Michigan.

The results could explain why dieting may backfire, leading us to eat more until the body meets its energy needs. We may even have hormones that help the brain distinguish real sugar from artificial sweetener, the study published the journal Neuron, said.

Globalization and Changing Lifestyles Alters Mediterranean Diet Pattern Of Natives
The famous diet is based on cereals, vegetables, pulses and a moderate intake of fish and meat, but tourism, urban development has altered the menu.

"We knew that the human brain could tell the difference between real and fake sugar, we just did not know how," said first author Monica Dus, assistant professor at the University of Michigan in the US.

For the study, researchers deprived fruit flies of food for several hours and then gave them a choice between diet, non-nutritive sweeteners and real sugar.

When the flies licked the real sugar, it activated a group of six neurons that released a hormone with receptors in the gut and brain. The hormone fueled digestion and allowed the fly to lick more of the nutritious food.

Diet or Exercise Interventions Prevent Excessive Weight Gain In Pregnancy
Interventions like low sugar diets, exercise only, or diet and exercise combined, all led to similar reductions in the number of women gaining excessive weight.

On the other hand, when the fly licked the diet sweetener, it never produced this hormone/digestive reaction because zero-calorie sweetener has no nutritional or energy value. In every case, the flies abandoned the artificial sweetener and chose the regular sugar because the starved flies needed the energy provided by the calories in the real sugar.

From an evolutionary perspective, sweet taste means sugar (traditionally from fruit or high concentrate carbohydrates) and a subsequent big energy boost. "Fruit flies cannot call out for pizza -- their brains expect calories if they eat something sweet, and that is why they chose the regular sugar," said Dus. "Fruit flies and humans share about 75% of the same disease-causing genes."

Unprocessed Lean Pork, The New Substitute To Chicken Or Fish In DASH Diet
Three ounces of tenderloin and fresh pork, uncured ham trimmed of visible fat, which is less than 10 grams total fat is a new option for protein in the DASH diet.

If our brains work the same way, this helps explain why diet foods do not satiate or satisfy us, and we gain weight while dieting, Dus said.

It is analogous to a person eating that entire sleeve of low-calorie cookies and the body telling her she is still hungry. She keeps snacking until she eats something with nutritional value that meets her energy needs, the study said.

Sodium-Rich Diet Shuns Down Digestive Tract and Suppresses Weight Gain in Mice
Mice on the high fat and high salt diet for 16 weeks had low weight gain of about 5 grams, which was similar to the mice on normal diet.

Source-IANS