It’s almost impossible to lose weight on a high carb diet
In a nutshell
The recommended high carbohydrate diet promotes obesity
With the way our hormones work, we may as well eat sugary dessert all day
It is almost impossible to lose excess body fat with exercise while on such a diet
This short article summarises discussions I heard at the 2nd Annual Scottish Public Health Collaboration conference in Glasgow.
I didn’t learn anything new on the subject of obesity but it did occur to me that there was a way to describe how someone following the recommended high carbohydrate diet can easily gain weight and struggle subsequently to lose it.
Let’s remind ourselves what we mean by carbohydrate-rich foods. I recently described a selection of common foods containing sugars (mono- and di-saccharides) and starches (polysaccharides) (Figure 1).
Figure 1: Common types of dietary carbohydrate
These are all quite common foods that most of us consume every day. Setting aside the obvious sugary things like fruit juice, jam, and banana, because of the way breakfast cereals, bread and rolls, and oat milk are manufactured, people consuming these things may just as well have sugary dessert for their breakfast (the image at the top of this article is of a breakfast spread in a hotel marketed as a health retreat in the middle of a forest).
Eating the things in Figure 1 causes the levels of glucose in our blood to rise. Glucose is a necessary fuel for our body but it is also very harmful if it rises too high in our blood. The body tries to keep blood glucose within a narrow range that ensures we have enough fuel but is always low enough to be safe. Any blood glucose that is not needed for fuel, is stored as fat. This made sense for our ancestors who would consume seasonal carbohydrate surpluses in the form of fruits, tubers, honey, etc. at the end of summer. They were essentially fattening themselves before a winter of likely food scarcity. During winter, they would (hopefully) live off their fat reserves plus whatever else they could find.
I’ve tried to represent the process of fat accumulation as three-stages in Figure 2. This is my own model and I presume that our ancestors probably entered the early stage and perhaps even mid stage before winter. Either way, their fat would likely have been gone by the end of winter.
Figure 2: Three stages of fat accumulation driven by ever-increasing consumption of carbohydrates
Our plentiful modern lifestyle and dietary advice to constantly consume a carbohydrate-rich diet means that our bodies are always experiencing the equivalent of a seasonal surplus. I represent this as late stage fat accumulation, an unhealthy metabolic state.
Late stage fat accumulation is a vicious cycle of never-ending fat storage that is symptomatic of metabolic dysfunction (Figure 3).
Figure 3: Continuous fat storage caused by over-consumption of carbohydrates
In this metabolic state, the human body is working overtime to counter a diet that it never evolved to experience and is not adapted to cope with. It will be very difficult to lose weight through exercise when we are constantly stimulating our hormone (insulin) to create fat stores.
Unfortunately living with a body that isn’t as aesthetically pleasing as we’d like may be the least of our worries. Those fatty areas are at least visible to us and remind us we need to do something if we want to. Remember, however, that excess fat is likely a symptom of metabolic dysfunction caused by a recommended high-carbohydrate diet. Other less visible symptoms of metabolic dysfunction can be developing within us without us knowing. These may include Type 2 Diabetes, fatty liver disease, heart disease, and high blood pressure.