to make sure you’re safe and healthy.
If you’re new to this world, I want you to understand the importance of individuality. I would rather empower you to create a unique way of eating that caters for your requirements, than suggest you follow a ‘one-size-fits-all’ approach.
Eating is a lifestyle, not an uncompromising ‘diet’. It’s a personal and experimental process that needs adapting as you and your environment change. This book, or any other book for that matter, will not contain the answer to everyone’s dietary requirements. But don’t despair! I’ve included principles of eating here that I think are applicable to most people, then the tweaking of elements really depends on you. Seek appropriate advice and get a second opinion if you have concerns about a specific medical condition.
Most diets out there promote a way of eating that is generally better than the typical Western diet of refined carbohydrates and a lack of fibre and micronutrients. So, no wonder there are so many success stories with a lot of them! This doesn’t necessarily validate these diets as a way of eating for all of us. But, it’s likely that you’ll incorporate elements and principles from a variety of diets to create the perfect way of eating for you. Because I get asked about these in clinic all the time, I’ve decided to give you my opinion on the most popular diets around: the good, the bad and the science that doesn’t always stack up.
Just cut the carbs!
+ Paleo, Low-carb high-fat, Atkins, South Beach, Ketogenic I know proponents of each of these diets will argue that these shouldn’t be grouped together because there are slight variations between each, but for simplicity’s sake, I have. Patients don’t appear to differentiate between them and lately I’ve been hearing the same line in my surgery: ‘So, Doctor, I’ve decided to cut out carbs. That’s good, isn’t it?’ Well, not necessarily.
The principles of Paleo, South Beach and Atkins are quite similar. They revolve around reducing your intake of carbohydrate and replacing it with varying proportions of protein and fats, with ‘low-carb high-fat’ (aka LCHF) and Ketogenic diets being the most excessive in terms of fat consumption. They’ve been reported in clinical studies to improve markers of diabetes103,104 and famously autoimmune disease105 in a number of protocols. The most exciting promise for Ketogenic diets is in treating childhood epilepsy and chronic pain.106,107
I think these types of diets do have a place for certain people looking to re-sensitise themselves to insulin after a longstanding over-indulgence in refined carbohydrates and sugar. There is small-scale evidence to show its potential in improving diabetes, insulin sensitivity108 and symptoms of PCOS.109,110
However, there is some evidence pointing toward high protein intake being similarly harmful as high carbohydrate intake, which is the trap a lot of people fall into when following these diets.111
And let’s not forget the side effects that include: constipation, halitosis, nausea, renal stones, osteoporosis and a potentially increased risk of bowel cancer (among many others).
A lot of people can’t maintain the diet for these reasons, and when they return to eating carbohydrate there appears to be a trend toward regaining all the weight they had lost with potentially worse outcomes and health risks than before they began.
On balance, long-term evidence to advocate these diets is lacking. Essentially, it’s a temporary fix. I appreciate the potential therapeutic value of these diets as a short-term strategy, but personally, I think a diet concentrated on plant nutrition far outweighs one focused on meat. More research is needed to validate the claims of these diets that drastically remove beneficial carbohydrate sources, and the lack of fruit, vegetables and fibre is something that would concern me. We know fibre is essential for proper functioning of our digestive system: our microbes feed off these materials and lack of fibre puts us at risk of bowel cancer.112 For those reasons, I can’t condone low-carb lifestyles long-term, but I don’t doubt that some people have found them beneficial and they may have a role in clinical care.
SIRT diet
While I welcome excitement about foods that have the potential to impact our genetic make-up, the SIRT diet’s focus on a small list of foods impacting some genetic pathways detracts from how multifaceted and complicated human nutrition is. ‘SIRT’ genes are what this diet is named after and increasing the activity of these genes (and the proteins they code for) is thought to reduce inflammation, control blood sugar and has been linked to reducing cancer risk.113
Yes, parsley, dark chocolate and green tea all increase SIRT gene expression but they also contain catechins, luteolin and a host of micronutrients that are essential for processes in our body’s cells. As do lupini beans, cavolo nero, broccoli, coriander, chilli and a whole bunch of foods that don’t fit a particular list. I think it completely misses the point to focus on an exclusive group of ingredients, and it doesn’t encourage a healthy relationship with food. Every ingredient deserves a platform.
Our grocery aisles are lined with unbelievable health-promoting foods, our seasons provide constant variety and our multicultural society introduces spices and herbs from across the planet. As I alluded to in the previous section, we are merely scratching the surface when it comes to the importance of different interactions between ingredients and our genes. I could have quite easily picked out a few fruits, vegetables and spices affecting one of many inflammatory pathways and called it the ‘NRF2 diet’, or how about the ‘TNF diet’? The Telomere diet? Do these sound scientifically valid enough?
The interaction between food and our genetics is a fascinating field.114 But it is one layer of a multi-faceted process that I haven’t made the cavalier attempt of trying to explain in its entirety. It certainly cannot be explained with one set of genes. Don’t let yourselves be patronised. Our understanding of these pathways is minuscule at best115 … and don’t get me started on ‘juice cleanses’!
The interaction between food and our genetics is a fascinating field.
5:2 diet
The science used to formulate intermittent fasting diets like the 5:2 diet is impressive.116 There appear to be benefits of cyclical fasting,117,118 but our way of eating needs to be sustainable119 and more importantly, enjoyable. Who wants to endure restricting themselves on a weekly basis … for life? I am convinced that some people have found benefits from this practice,120 but if I were to tell the majority of patients I see in clinic to reduce their calories to 500 for two whole days, I know exactly where they’d be telling me to go!
And this brings me nicely to another topic. I don’t count calories. For the majority of people it’s a complete waste of time because it shifts the focus toward indiscriminate numbers on packets of food and away from what is actually important: the quality of food we introduce into our body. Clearly, a bag of sugar compared to an equal calorie content of spinach is going to have drastically different effects on our body. Calorie counting does not account for this difference. It focuses unnecessarily on a logic that was once thought to be scientifically accurate but is now shown to be flawed in many ways.
+ A NOTE ON CALORIES
The long-held idea that excessive calorie consumption leads to weight gain and reducing calories leads to weight loss is simply not accurate. Also, the metabolism of food is likely to differ from person to person depending on a host of factors such as their microbiome population, their genes, activity level, timing of meals and many
