Brillat-Savarin made the famous quote “Tell me what you eat, and I will tell you who you are.” This is often misinterpreted as “You are what you eat”, which may actually be closer to the truth in biological terms – but that was not what the French gastronome meant.

What he intended to say was that a person’s upbringing and character may be judged in some way from personal dietary preferences – the choice of ingredients, method of cooking and presentation – for food has a way of defining social differences and bonds.

This may have been more true in the past but it is still somewhat relevant even today, and may be due in part to our conditioned response to food.

As a curious example, the Scottish dish, haggis, was actually developed during times of famine to utilise every scrap of a slaughtered sheep – and therefore it contains, amongst other bits, the chopped lungs, hearts, liver, stomach, tongue, etc, bulked up with various grains and any available spices, and the resulting gunk is then stuffed into the intestines and boiled or roasted.

The original versions were allegedly so vile that people had to drink whisky to hide the taste – and this tradition of swigging whisky with haggis continues to this day, even though modern haggis is actually rather palatable. As such, the love of haggis (especially on Burns Night) is one of the traits of most Scots.

The shorter-living Americans

The physiological factors behind our food preferences are today sources of huge pleasures as we now have access to an immense variety of foods and cuisines from around the world – and many of us can’t wait to taste the next dish from far-flung places like Bolivia, Ethiopia, or whatever country or town or even village gets into focus by the media.

But there are downsides to this as well, and some of these pitfalls may actually end up being rather dangerous – and that is simply because the reasons why we like food are now known and can get exploited.

I was pretty intrigued to read some years ago that many of the current generation of Americans are probably going to have a shorter lifespan than their parents, the first time in peacetime history that a newer generation would live briefer lives than the previous generation in a developed nation.

And it is due mostly to diseases caused by their diets. It was incomprehensible really, as all modern countries now have food safety standards, better education, superior medical care and easy access to lots of hygienic food.

However, most of the Americans fated with shorter lives tend to be poorly educated and from the lower social orders of society, who usually also cannot afford proper medical care or the best quality food. They also tend to work longer hours and cannot spend the time to cook at home after work.

This inability to prepare and eat proper meals at home might be regarded as unhelpful, but it is compounded by the easy access to a vast variety of inexpensive fast and convenience (frozen) food – it is often cheaper to eat these than to buy the raw ingredients. And so that is what most of these people eat, practically every day of their lives.

Before we get judgemental about fast and convenience foods, let’s double-check what the previous generation was eating – and then we find that they also had access to a lot of fast and convenience food, and were eating a lot of it too. So if the dietary environments between the two generations are more or less the same, then either the food had changed between generations or maybe there are some other factors of which we are not aware.

The fizz and the water

So let’s start by investigating a simple modern home situation: When my children were younger, I noticed a somewhat odd but common occurrence. If we had a two-litre bottle of a fizzy drink in the fridge next to a two-litre bottle of mineral water, the fizzy drink will get drunk far, far faster than the mineral water.

Sometimes, two litres of fizz will disappear before we had even finished unloading the rest of the shopping – but the mineral water will still be there.

As I’m always curious, I looked into the ingredients of the fizzy drinks and unsurprisingly, there is a lot of sugar along with flavourings and preservatives – and then it struck me that these drinks are something that humans would not have encountered until the 20th century. If anything, people should prefer plain water as that is what humans have been mostly drinking during the evolution of our species.

But the reality is, given a choice, it seems that humans seriously prefer the taste of sugary, fizzy water laced with artificial flavours and preservatives to plain mineral water.

Another observation is that people can easily finish more than two glasses of fizzy soda at one go but they are often incapable of drinking two glasses of plain water. In physiological terms, fizzy drinks cover items 1 to 4 on the list of desirable food factors and hence it is really no surprise why humans like carbonated sweet drinks.

But it is still curious why we can drink a lot more gassy sweet water than plain water – and the question is whether it is all to do with the taste or is it something to do with the ingredients.

Dance of hormones

Eating happens because of a little dance between two hormones in our bodies. We feel hunger because of a hormone called ghrelin, which is produced when the stomach is shrunken and empty.

Ghrelin is also associated with the nucleus accumbens, a part of the brain that is involved with reward and reinforcement – it’s the same part of the brain that stimulates us to succeed at our tasks.

As the stomach expands during eating, the level of ghrelin falls correspondingly. And as we eat our food, the body produces progressively more and more a hormone called leptin – this is also called the satiation hormone as it signals to the brain that we have ingested enough calories and therefore we should stop eating.

Leptin is also produced automatically late at night, ensuring that hunger pangs do not disrupt our sleep. Anything that disrupts the production of leptin or increases our tolerance to it will cause us to eat more.

A coincidence?

As I work a lot with statistics and maths, I have to clarify now that correlation is not always proof of causation – however, a lot of researchers have been investigating a link between the current increase in obesity and dietary diseases in the United States and the increased consumption of a monosaccharide sugar called fructose, usually included in processed foods and drinks in the form of High Fructose Corn Syrup (HFCS).

The other coincidental link is that HFCS became industrially available from only around the middle of the 1970s and has been heavily used since then – and this period coincides with the increases in obesity and dietary diseases.

Fructose in HFCS is a very cheap sugar, and also very sweet, around 1.73 times as sweet as sucrose (cane sugar) and over 2.3 times as sweet as glucose.

One perceived area of concern is that there are strong indications in mice that large doses of fructose cause an increase in leptin tolerance, which means that they will eat more and become obese as a result.

The mice also appear to exhibit insulin resistance resulting in poorer processing of blood glucose, a symptom of diabetes. With tests on healthy young humans, fructose does not appear to have any major short-term deleterious effects although longer-term problems do seem to begin to appear if 25% of the daily calories are derived from fructose.

Oddly, for human diabetics, some research suggests that small amounts of dietary fructose might actually be beneficial as it has a lower Glycaemic Index (GI) than other sugars and hence will cause less severe blood sugar spikes.

So perhaps purely focussing on fructose or HFCS may or may not lead us to any conclusive answer to the question whether there is any difference in the food eaten by the current generation of low-income Americans and their parents.

eatWhat is probably quite different is that convenience food today is definitely rather more tasty than convenience food a generation ago – note that I do not say it tastes better, but modern food is more “tasty” in general.

Just think of a frozen pizza meal 10 years ago compared to today. Thanks to the billions spent on continual research and development by the food industry, modern convenience foods have better textures, stronger flavours, and are easier to eat and enjoy – they are also likely to be packaged more attractively and relatively cheaper compared to a generation earlier.

Perhaps the industrial practice of including cheap HFCS into modern foods might induce people to ingest more calories than they should (possibly due to the inhibition of leptin) – but overall, the probable reality is that many people are either compelled or actually prefer to eat modern convenience foods and are therefore ingesting too much sugar (and other potentially questionable ingredients such as white flour, processed meats, fats, preservatives, colourings, additives, etc) as a result – and getting fatter, sicker and dying earlier.

You can’t beat the house

The food industry understands intimately all the physiological and psychological factors behind the eating habits of every social group in every major market – with the constant research done by the food industry on what and why we like to eat, it would be pretty impossible to resist all their food offerings in their pretty packages.

Also, who has not experienced something similar to the frustration of making the effort to steam a lovely fresh fish only to have a child complain that fish fingers taste so much better?

The range of convenience and fast foods get more tempting each year and most humans simply cannot resist them. And why should we, provided they are economical, healthy, wholesome as well as “tasty”? Modern junk food is usually priced very attractively so it becomes a double-whammy for lower income groups.

I candidly confess I sometimes like convenience and fast foods too – though what I usually do is look at the side of the packaging and check out the calories and ingredients. If there are things on the list I don’t understand or don’t like, then I think that perhaps my family and I shouldn’t be eating so much of it – that just seems like common sense.

However, I can completely understand if other people are more seduced by the marketing, “tastiness”, advantages and choices offered by convenience or fast foods – and are less discerning.

The food industry may technically be right in saying that they don’t force people to eat (or over-eat) their products, but it is clearly an option which they would prefer as it would mean more profits – and these profits then justify the huge expenses behind their research into what and why we like to eat.

In summary, humans are physiologically compelled to like food presented in certain configurations – these preferences were meant to assist in our evolution and be selective when food was scarcer.

Scarcity of food is generally not a problem now for people living in developed countries – and with the wild interchange of cuisines from around the world, it is truly an exciting time for sensual enjoyment and gastronomy as we learn and develop more preferences for new comestibles.

The other side of the coin is that industry has also discovered that basic food ingredients can be commercially engineered to become extraordinarily desirable to eat.

Perhaps humans in developed societies are now in the phase where they need time to adjust to the new characteristics of modern food – and become wary of over-indulgence.