3.17 Ketogenic Diets and Ketosis
Many popular diets restrict the consumption of carbohydrates, and these are generally referred to as Ketogenic Diets (KD). This style of eating can be difficult to sustain because the first few days, and sometimes weeks of strict KD aren’t much fun. A person may feel depressed, and even mentally or physically impaired. This response isn’t surprising considering the role of carbohydrates/glucose in our diet. The brain and central nervous system (CNS) rely almost entirely on the availability of glucose for energy and (feel good) mood regulation. In fact, on a daily basis (with healthy conscious eating) the brain will use up to 60-70% of the total body metabolized glucose [5].
There are at least twelve KD eating styles but what they have in common is that after 3 – 4 days (sometimes longer) without carbohydrate intake (KD or fasting) the CNS will find and use alternative energy sources [54]. For most people, the liver will eventually produce ketone bodies that can be used in place of glucose for energy [54]. However it takes time for our brain chemistry to adjust to ketosis, and for us to feel “normal.” Once the body adjusts, ketone bodies are efficient energy sources, ghrelin levels increase, and we experience a reduction in appetite [54]. The challenge however with KD (and with most restrictive eating styles) is that restricting activates compensatory brain responses that increase our perceived “reward” value of food as well as our preoccupation with food.
These responses simply makes us think about and crave UPND foods. If we’re unaware of why this is happening, any weight loss due to restrictive dieting may be short-lived. To the point, our brain needs time to adapt to changes with respect to our (BMI) percentage levels of fat. If we try to lose weight too quickly our brain (in survival mode) may desperately attempt to have us return to a previously comfortable BMI composition.
One of the concerns with any weight loss regimen, particularly the newer medications that reduce appetite by signaling “fullness” in the brain stem, is that in a state of starvation we may actually be losing equal amounts of fat and muscle. This loss of muscle tissue (which can be measured by Dexa scans) impairs cellular recovery at the most profound levels and can eventually lead to the onset of sarcopenia. It’s strongly recommended that any change in eating styles be supervised by a medical provider to avoid issues with nutrition, cholesterol, fatty liver disease, blood sugar, sodium levels, and more.
Speaking of medical providers, here’s some inspiration. Doctors in a practice in England recognized that over a 30-year period there was an 800% increase in the prevalence of Type 2 diabetes in their practice (1987 – 2017) [55]. To address this problem, they began a program where participants opted to follow a lower carbohydrate diet (LCD) for an average of 23 months [55]. For those who had Type 2 diabetes there was a 46% rate of remission. For those at the pre-diabetic phase (HbA1c 42 to 48 mmol/mol), a 93% rate of remission was achieved! This program relied on an integrated approach to wellness [55]. Aside from LCD nutrition guidance, participants were provided with regular follow up appointments, an evening support group led by a psychologist, as well as family education on nutrition and meal preparation [55].
