For many years fat was known as the number one diet enemy. In more recent years it has been sugar that has been demonised as the devil when it comes to Western society's burgeoning obesity epidemic. But there is actually one thing worse than either fat or sugar — that's fat and refined carbohydrates combined.
And it's a mix that is found in many of our most popular foods including ice cream, chocolate, cakes and yes — doughnuts.
Brain analysis has repeatedly identified that a number of brain centres are stimulated when concentrated mixes of fat and sugar are consumed, building reward circuits via the neurochemical dopamine.
The more of these foods that are consumed, the more dopamine the brain is exposed to. Over time this results in the brain becoming desensitised, requiring more of these foods to achieve the same amount of pleasure initially experienced.
It is this long-term programming effect that somewhat explains the chronic overeating of high calorie, rich foods — the ability to down an entire tub of ice cream in one setting when others can only tolerate a scoop or two.
It is also explains why the complex food concoctions human beings have developed in the form of ice cream filled with lollies, pastries filled with sugars and fast food loaded with fats, processed carbs and salts have had a profound effect on the types of foods human beings crave and overeat.
So, while we often isolate the carbohydrate sugar, we also need to remember that refined carbohydrates and processed starches can be just as damaging to cellular metabolism. For this reason, processed potato and snack foods cannot be forgotten when it comes to the potentially damaging effects of processed carbohydrates.
So before you rush out and ban all sugar from your diet, it may be more pertinent to pay more attention to these baddies — the most energy-dense foods many of us indulge in far too often.
The French may buffer theirs with red wine and small portions, but with a chocolate pastry giving you a massive 500 calories (dieters only need 1200-1500 in a day), 24g of fat and more than 60g of carbs thanks to the layers and layers of butter-clad pastry, there are few foods as quick to eat with as many fat and carb calories as that of filled pastries.
The things about muffins is that when we have small homemade versions based on wholemeal flour and plenty of fruit they are a rather nutritious option. On the other hand, when our favourite muffin is jumbo-sized and flavoured, even double flavoured as is the case with a chocolate Nutella version, your muffin can give you as much as 400-500 calories, more than 20g of fat and more than 50g of carbs.
Now I am not talk a piece of plain bread here, I am talking about the fried, slathered in oil thick slices of bread in a massive serving size which add up to give you a massive 600 calories, 38g of fat and 58g of carbs per serve.
You were probably expecting this one. The tasty mix of milk, vegetable oils and plenty of sugar is one of the most energy-dense foods out there, especially when you calculate energy density per gram serving (let's be honest who stops at 1-2 squares). This means that just half of your favourite block of chocolate has more than 500 calories, 30g of fat and 58g of carbs.
It may come as a surprise to hear that it is not the burgers that cause us as much trouble in the fast food stakes but the jumbo sized serve of fries we scoff down with our burgers and soft drink. The thinner the fries, the more oil they absorb which is why a medium size serve of fries clocks in at 370 calories, 20g of fat and 41g of carbs.
A weekend favourite dating back to our school days, pies are not much better but it is the fatty meat and dense pastry in a sneaky sausage roll that gives you almost 500 calories per serve, almost 30g of fat and 48g of carbs.
Potato chips are not so great for us, but when it comes to the snack foods with the highest energy densities, extruded cheese snacks like Cheezels win hands down. A 100g box (remember how light they are) equates to a massive 680 calories, 38g of fat and 70g of carbs — one of the highest of all foods out there and one of the ones best avoided altogether.
Susie Burrell is a dietitian and nutritionist. Follow her on Twitter @SusieBDiet