So not only calories have a objective in a healthy metabolic activity, the perception of sweetness helps the brain too.
Naturally, energy is signaled by sweetness; the calories are more when there is a greater sweetness.
It does not register that calories have been consumed, which could lead someone to end up eating more. He says that the calories are only half part of the entire equation and the sweet taste perception will occupy the remaining portion.
They found when there was a "mismatch" between sweetness and calories - as is often the case with diet drinks or foods because they are not as sugary - the calories fail to trigger the body's metabolism.
When a beverage is either too sweet or not sweet enough for the amount of calories it contains, the metabolic response and the signal that communicates nutritional value to the brain are disrupted, according to study published August 10 in the journal Current Biology.
Responding to the study, published in the journal Current Biology, Tam Fry, of the National Obesity Forum, said: "This research should be enough to convince you that artificial ingredients, whether they be in food or drink, can screw up your system even though they may sound healthy".
"Our bodies evolved to efficiently use the energy sources available in nature", Prof Small told Yale News.
Dana Small, the senior author and Professor of Psychiatry at Yale University School of Medicine, said: "A calorie is not a calorie". According to them, these findings establish the link between artificial sweeteners and diabetes in previous studies.
Professor Dwyer added that the mismatch may have a negative impact on weight and metabolism, but the link between unprocessed calories and metabolic diseases and health needs further study.
In the new study, brains of 15 participants, when they drank diet drinks were scanned and were then compared with regular beverages. In nothing less than a shocker to many, the results were opposite to what people believe.
"Our modern food environment is characterised by energy sources our bodies have never seen before".
Professor Tom Sanders, of King's College London, said: "Saying a calorie is not a calorie is gobbledegook". He argues that artificial sweeteners can not cause weight gain.