The lactic acid build-up in my arm had become unbearable. I was starting to sweat. I didn’t think slicing bread could be this difficult. But this wasn’t just any bread. This was proper bread. But was it healthy?

To many in the health community, bread is the enemy. A food that makes you fat and gives you diabetes. A food to be avoided at all costs. Resolutely unhealthy. But, as with most foods, things are not that black and white.

Let’s push the elephant out of the room first. Bread is predominantly carbohydrate, and, according to some, carbohydrates are uniquely fattening. This is not true.

Now that’s out of the way, let’s get to the problem of defining how healthy (or unhealthy) a food is.

No food can be definitively categorised as healthy or unhealthy for every single person. It depends on the individual and on the context. Coca-Cola is seriously unhealthy for the vast majority of people. But for a type I diabetic on the verge of a hypoglycaemic coma, it may be life saving. Raw almonds are a relatively healthy food for most, but they could be deadly to someone with a tree nut allergy.

You get the point.

For most people, there are two metrics against which we can judge the healthiness of a food:

1. It’s nutrient-density: The quantity and variety of essential nutrients it provides
2. The extent to which it regulates appetite: The key mechanism for determining calorie intake, energy balance, and therefore body weight and metabolic health. There are two (interconnected) systems involved in appetite regulation:
   • Lipostat
   • Satiety

So, how does bread stack up here? That brings us to another problem – what type of bread are we talking about? Let’s give bread a fighting chance by choosing the healthiest type of bread: Wholemeal, traditionally-made sourdough.

The healthiness of most foods is a continuum, from most healthy to least healthy. The most healthy is typically the least processed version (i.e. the food closest to its natural state), and the least healthy is typically the most processed version. In the world of bread, wholemeal sourdough made in the traditional way is arguably the least processed (most healthy) version of bread, while factory-made white sliced is probably the most processed (least healthy).

Wholegrains are more nutrient-dense (per calorie) than refined grains, but not by as much as you might think. Wholegrain bread has a higher satiety score – in other words, it’s more filling per calorie – than white bread, primarily due to the higher fibre content. Wholegrain sourdough, in particular, is far less convenient than white sliced – it’s harder to come by, more expensive, harder to cut, and harder to eat – and convenience is one of the major regulators of appetite and food intake. The lower degree of processing itself in wholemeal sourdough – independent of all other factors – is also likely to reduce appetite and calorie consumption.

So, wholemeal sourdough is healthier than white sliced, and probably the healthiest type of bread. But how does it compete at big school, against all other foods?

Not bad. But not great.

Wholegrains are ranked 18 out of 25 food groups in terms of nutrient density, only five places above refined grains (which is just above “sweets”). The top ten for nutrient density looks like this:

1. Organ meats
2. Shellfish
3. Fatty fish
4. Lean fish
5. Vegetables
6. Eggs
7. Poultry
8. Legumes
9. Red meat
10. Milk

Eating a lot of wholegrain sourdough may not be advisable, because it would crowd out some of the much more nutritious foods. But, then again, it may help us eat some nutrient-dense foods that we perhaps otherwise may not. What goes really well with chicken liver pate, sardines, or poached eggs? Yep, wholemeal sourdough bread.

What about appetite regulation and calorie intake? Wholemeal bread competes reasonably well in the satiety stakes – it’s about as filling as eggs, and not quite as filling as meat or fish. But that’s wholemeal bread on its own. Plain. The more bland (less palatable) a food is, the less we tend to eat of it. Bread’s favourite partner, of course, is butter (or olive oil and balsamic vinegar if you’re in Italy). This combination of carbohydrate and fat makes bread and butter much more palatable and rewarding than plain bread, wholemeal sourdough or not. As a result, we tend to eat more of it.

Is bread bad for you? Highly processed white bread certainly is – it’s very nutrient poor and has a very low satiety score (in fact, white bread is used as the benchmark for low satiety in this study). Traditional wholemeal sourdough is not bad for you – it has more nutrients (just) than white bread and regulates appetite reasonably well. I wouldn’t say it’s good for you either. But I would say that it can be part of a healthy diet, especially if you go easy on the butter and use it to eat more of the most nutritious foods like liver, fish, and eggs.