Food is a battleground. Not a day goes by without what we eat being scrutinised in newspapers or TV. From the Great British Bake Off to the Great British Menu, there is much focus on the glories of food as we shift into autumn. It is an awkward contrast to the dictatorial slimming programmes broadcast a few channels away, and tabloid headlines bearing claims about the latest "wonder" diets.

The contradictory messages are enough to make many people switch off from healthy eating messages and retreat to old habits. After all, what we eat is a large part our identity – our diet and the food we eat evoke childhood memories, reflect our country of origin and its dietary traditions, the cooking skills of our family members that were passed on to us (or not), and the social place of food in the home and our communities.

We all have a few foods that can instantly awake a memory or two. I grew up in France and garlic rice is my staple – a little odd, but always satisfying, whether in my mother’s kitchen or in Scotland. A life without garlic rice would be, for me, a life with fewer opportunities to remember good times.

It is our food roots that make speaking about food and diet objectively so challenging – in some ways, is a diet overhaul not a stand against who we were and where we come from? Is our interpretation and understanding of what we read, hear and discuss about food and drink coloured by our lifelong experiences?

There are many reasons to change ones diet, whether over health concerns or to lose weight to look and feel better. Not all changes need to be dramatic, small changes can go a long way.

In Scotland, where two in three adults should be making changes to their diet to lose excess weight, this could have the welcome effect of decreasing the risks associated with obesity – including poor cardiovascular health, diabetes, and some cancers.

The remaining 1 in 3, far from ignoring what they eat, should keep a mindful eye on their plate, since weight gain is generally associated with ageing.

In truth, the best diet is the one that you can stick to, as long as it provides the basic elements that sustain health. Energy for the body to function, essential nutrients, hydration.

It should be simple but it's not. Even the basic principles are difficult and confusing for many people, leading to ignorance over how to prepare a healthy meal. This confusion opens the door to quick fixes to complex problems such as obesity.

The most recent fad, the all-meat diet proves the point that regardless how little sense a diet makes (scientific or otherwise), it will draw interest.

Popular diets are not a new symptom of our modern society – in fact, the same principles are warmed up and served as new on a fairly regular basis – William Banting wrote the first low-carbohydrate diet book in 1863.

It is the subtle mix of branding, personal stories, attractive pictures and endorsement, under an occasional veneer of pseudoscience that make a fad diet.

Meal plans which offer detoxing or superfoods are more likely to impact on wallet than waistline, yet they retain a strong following. This is not necessarily an indictment of the credulity of dieters, but a sign that people are looking to eat more healthily, a sign of hope.

We need clear, plain and unbiased information to dispel this confusion – yet we most often hear entrenched, hyperbolic views on what to eat (and how, and when).

Low carb (goodbye, garlic rice), low fat, no meat, all meat, dairy free – there is something out there to suit all styles and beliefs. The thing is, diets that work for a few will not necessarily work for the many, and attempts to present one dietary pattern as the simple and only ‘truth’ are counter-productive. Most concerning is when, through the prism of personal success, dietary strategies turn into cults.

This is the peril of confirmation bias, when anecdotes are turned into evidence, nutritional science findings are parsed for details confirming ones existing views, and when the lids are lifted on supposed conspiracies at the risk of distorting the conversation and harming decision-making.

The public deserves to have the necessary information to make decisions about what and how much goes on their plate. This should not be sensational. Or magical, or driven by egos or beliefs that supersede reason. Just plain facts. Scientific progress is incremental and geared toward building a larger body of evidence. Nutritional science is good at generating new ideas and testing hypotheses – the findings are often not very sexy, at face value, but complex and useful.

It is this complexity we should celebrate, not boiled-down “truths” which ultimately switch off our ability for informed decision-making about what goes in our plates.

Dr Emilie Combet is a nutritionist at the University of Glasgow