Bread is not for ducks – Questioning nutritional advice for optimum performance at work

It’s not hard to find healthy eating information online, lots of it conflicting and based on outdated science. A quick browse over the NHS’s ‘eat well guide’ offers me some basic guidelines for what a healthy diet should look like:

– Eat 5 portions of fruit and veg a day

– Base a third of your diet around starchy carbohydrates such as potatoes, bread, rice and pasta

– Eat fat sparingly and choose low-fat alternatives

Fruit

Five portions of fruit and veg a day. A recommendation we’ve been sold ever since it was thought up by a partnership between the National Cancer Institute and the Produce for Better Health Foundation in 1991.  The problem is it’s plucked entirely out of thin air and not based on science. What’s more, is the Produce for Better Health Foundation is sponsored by so many logistics firms, specialist producers, and general fresh produce firms it’s almost comical how much of a vested interest they have. ‘So What!’ I hear you say, ‘fruit and veg is healthy’. I’m not arguing against eating vegetables, but I do think that fruit has enjoyed a free ride alongside vegetables as being an equivalent healthy option when that might not necessarily be the case.

Most people I know that follow the 5 fruit and veg a day rule tend to focus more on the fruit part than the veg part. After all, it’s often easier and tastier to throw in a sweet piece of fruit as a snack than to increase your vegetable consumption. Why is this an issue? Fruit is typically marketed as being high in vitamins, minerals and phytonutrients, as well as being a good source of fibre and containing a large number of antioxidants. While fruit also contains up to 16% sugar, evenly distributed between fructose and glucose, with an apple containing the same gram for gram sugar content as a can of coke.

What’s the problem with fruit?

The metabolism of fructose produces a chemical called Uric Acid, which interferes with the production of Nitric Oxide. Nitric Oxide is responsible for a whole host of healthy bodily functions and a lack of it can cause high blood pressure. Nitric oxide also inhibits the production of Leptin, a satiety chemical responsible for making you feel full, which is why after snacking on fruit you’ll often feel hungry again only a short while later. While eating a piece of fruit here and there isn’t going to give you anywhere near the amount of fructose required to cause any real issues, and fruit does contain some beneficial compounds; there are often better sources of vitamins, minerals, and antioxidants. Green leafy veg is almost always higher in vitamins and minerals than any fruit, with spinach containing 5x more vitamin C than an apple, and broccoli containing 20x more. Green leafy veg such as chard is also categorically higher in vitamins such as B, E, D, and K1 when compared to fruit. When it comes to antioxidants a single cup of black coffee has been shown to contain over 30 times the level of antioxidants compared to an apple.

Carbohydrates

Traditional advice around carbohydrates is to make starchy carbohydrates such as potatoes, bread, rice and pasta around a third of your diet. Aside from health concerns regarding eating lots of food likely to spike your blood sugar. For example, eating high glycemic index foods such as bread and pasta, recent science points to increased gluten consumption as an exacerbator of various health issues.

Gluten is the general name for wheat proteins typically found in foods such as bread, pasta, and cereals. It’s responsible for holding grains such as wheat, barley, and rye together, giving pasta and bread that chewy, flexible texture. While Most of the population can consume gluten with no discernible side effects, a small percentage of the population, around 0.5% – 1%, are diagnosed with Celiac disease, a condition characterised by extreme reactions to gluten proteins causing gastrointestinal issues along with some other pretty nasty side effects.

So what’s the problem if most of us can eat gluten without any issues?  What people don’t know is 95% of people with Celiac disease are undiagnosed. This can manifest in a variety of different ways; from bloating, to joint issues, to depression, and is why the condition often goes undetected. Aside from people with extreme reactions to gluten, it’s estimated that anywhere up to 40% of the population are Non-Celiac gluten sensitive and may be experiencing mild symptoms unaware that they might be gluten related.

What’s up with Gluten?

As Gluten is digested by the body, it gets broken down into separate molecules, Gliadin and Glutenin. Gliadin is completely indigestible by the human body and in people that are gluten sensitive can provoke an immune response causing the body to treat it as a foreign body and reacting by eliciting an immune response causing inflammation. While inflammation is a helpful response when fighting off infections, it’s not something you want to be happening every time you eat a meal. Gluten consumption also increases the production of Zonulin, a chemical responsible for allowing gut contents to pass through the epithelial lining, this can lead to Gliadin leaking out of the gut and causing the aptly named condition ‘Leaky Gut Syndrome’ where undigested food and toxic chemicals can leak out of the gut and cause issues where they don’t belong.

Excessive gluten consumption is also hinted at as being a large factor in the obesity epidemic, for example, the obesity rate in Japan is only 3.5% compared to Americas 30%. Both countries eat comparable levels of rice and wheat combined, but the ratio of wheat to rice consumption in America is almost double that of Japan’s. With Celiac disease increasing fourfold over the last 50 years, and more people feeling the negative side effects of eating gluten, why are modern dietary guidelines still suggesting these foods make up such a large portion of our diets?

Fat

Eat fat sparingly and choose low-fat alternatives. Advice that’s been around since the 1970s when saturated fat was demonised in a study by Ancel Keys. This study concluded that countries with higher fat consumption had more heart attacks, makes sense right? The more fat you eat, the fatter you get, causing cholesterol to rise and arteries to block leading to heart attacks. This is simply not true, the original study hand-picked 7 countries out of a total of 22 to fit with the hypothesis that fat causes heart disease. Keys got this conclusion accepted by the USDA, American Medical Association, American Diabetes Association, and the American Heart Association. This misinformation wasn’t just perpetrated in the US either, multiple other countries adopted a similar anti-fat anti-cholesterol stance which remains prevalent in common health advice offered today by institutions such as the NHS.

Why you should say no to low-fat alternatives

As a result of this attack on saturated fat, food producers replaced saturated fats with unsaturated alternatives. Some of these alternatives required chemically altering the structure of vegetable oil through a process called hydrogenation, which of course later turned out to contain dangerous levels of trans-fats which actually are proven to be bad for both heart health and cholesterol levels. The typical low-fat alternatives that are touted as being a healthy option in supermarkets usually replace fat with sugars and sweeteners. More modern studies have pointed towards sugar as being the real cause for heart disease, not fat, with one study finding that people who got 17% to 21% of their calories from added sugar had a 38% higher risk of dying from cardiovascular disease compared with those who consumed 8% of their calories as added sugar.

While most people these days are probably okay with eating a lower carb diet to improve health, most people are still not completely comfortable eating a high-fat diet. Looking at food from an evolutionary standpoint, removing fat from our diets doesn’t make sense. Our brains are the most metabolically expensive organ consuming 25% of the adult metabolic budget. To adjust for the high energy cost of a large brain, our guts shrank because they also require a lot of energy to run, so our gut became less efficient at getting energy from more fibrous foods and became dependent on more bio-available, nutrient and energy dense foods.

I’m not saying don’t eat fruit, or to completely cut bread from your diet and to only eat high-fat foods, I’m simply asking why these dietary recommendations have remained the same, despite compelling evidence to suggest they don’t tell the whole truth.