Leading expert says food scientists combine sugar, fat and salt in ways that make junk foods like burgers, chips, cold drinks and pizzas impossible to resist.
Th expert claims that cereals and ready meals can act on the brain's reward centers in the same way as tobacco.
David Kessler, former head of the US Food and Drug Administration (FDA), claims that manufacturers seek to trigger a "bliss point" when people eat certain products.
"It is time to stop blaming individuals for being overweight or obese. The real problem is we have created a world where food is always available and where that food is designed to make you want to eat more of it. For millions of people, modern food is simply impossible to resist," The Times quoted him, as saying.
In his new book, The End of Overeating, David suggests food manufacturers use precise combinations of fat, sugar, salt and texture to make foods "hyper-palatable".
To reach the conclusion, Kessler with researchers at Yale University conducted a study using functional magnetic resonance imaging techniques.
About 50 percent of obese people and 30 percent of those who are overweight were prone to so-called "excessive activation", the study found.
"The right combination of tastes triggers a greater number of neurons, getting them to fire more," said Kessler.
"The message to eat becomes stronger, motivating the eater to look for even more food," he added.
Kessler said: "Many of us have what's called a 'bliss point' - the point at which we get the greatest pleasure from sugar, fat or salt.
"As more sugar is added, food becomes more pleasurable until we reach the bliss point, after which it becomes too sweet and the pleasure drops off."