A dark colour and seeds on the crust mean nothing. That is the whole point, and it is exactly what half the shelf in every supermarket relies on.

Nutritionist Elena Pareja says it plainly: bread is wholemeal only when it is genuinely made from wholemeal flours. Not when it looks wholemeal. The colour can come from malt, from caramelised sugar, from grain colouring - additives that carry not a gram of fibre. Seeds stuck on top are decoration too, not composition.

The second thing that demolishes the marketing: the calorie difference between wholemeal and white bread is minimal. If you are buying wholemeal in order to eat fewer calories, you are buying for the wrong reason. The advantage is in the fibre - it gives longer satiety and eases intestinal transit. That is the real reason, and it has nothing to do with the number on the label.

Pareja says something that sounds obvious until you try doing it: read the ingredients list and check the percentage of wholemeal flour or whole grain. Not the front of the packet. The front is an advertisement. The ingredients list is the only place where the manufacturer has to tell the truth, and that is precisely why it is printed smallest.

Nor is there a universal daily amount. It depends on how much energy you burn - not on a figure somebody repeats on television. What Pareja advises is different: look at whether the bread is colliding with other sources of carbohydrate in the same meal. Bread next to potatoes next to rice is not a question about bread, but about the whole plate.

And the last point, which is actually the biggest: when losing weight, the overall dietary pattern and total energy intake matter more than any single food. So no bread on its own will make you gain weight, and no bread on its own will make you lose it. But the industry lives off precisely the opposite belief - that one cleverly bought packet solves your entire diet.