Intermittent fasting is the hottest topic in diet related research and for good reason. Age old wisdom backed by preliminary research shows that abstaining from food for lengths of time can deliver truckloads of benefits. Fasting can improve metabolic and cardiovascular health, boost the immune system and is likely very good for the brain! Personally I try for a 18-20 hour fast once per week and every once in a blue moon will go for a multi day fast. Intuitively one would assume not eating for most of the day or even for days at a time must be good for weight loss as well. Unfortunately the answer is not so simple, in fact the opposite may be true.
In my 17 years of personal coaching, I have noticed a startling phenomena, which as it turns out is backed by scientific research. I have seen case after case of people over-exercising or participating in a starvation level diet, only to see their weight loss efforts stall out or backfire. In recent years I have noticed another disturbing trend. People who fast to lose weight, getting great results initially, only to see a marked weight GAIN in subsequent months and years. Specifically an accumulation in belly fat, which is the most dangerous kind of fat for long term health. I wish to discuss two separate phenomena which may be at work here. The first is the concept of “Set Point” the second is “Allostatic Load”
Set Point simply means that your body gets used to being a certain weight, it likes being at that weight, and it will use its considerable power to stay at that weight. So lets say Jessica gains 15 kg over the course of her 30’s and then decides to diet it off, the organismic system will resist her efforts by manipulating energy balance. It can do so in many ways. It can make her binge eat at night, confounding her strict daytime discipline. It can shunt energy away from the brain, making her lethargic (the brain is one of the big calorie hogs of the body). It can reduce muscle or even bone mass, making her weak and frail. Most commonly, it will simply hunker down until the period of famine (diet) is over and then when the 3 months are past it will come back like a roaring furnace consuming everything in range and putting her back to where she started or worse.
It is worth noting that none of this is Jessica’s fault. Her body is doing exactly what it is supposed to be doing which is to prioritize the survival of life. For 3+ billion years organisms tried to maximise energy intake, it is thanks to that feature we get to write blog posts and drink coffee today. If she is to lose weight and keep it off, she will need to take a more compassionate approach towards herself by dieting and exercising in a way which is sustainable for the long term. Sustainable exercise is first and foremost fun, has a social component (directly or indirectly), and must feel necessary. Getting in the habit of walking or biking to work has a feeling of productivity and the brain feels it is doing something which is needed, even though you can technically take the car. If you dread your workouts, at some point you will stop doing them or compensate with some form of overconsumption.
The second phenomena which may be responsible for weight gain in fasters is allostatic load. This area needs more research, but the idea is that if you are overstressed and the body doesnt have time to recover from those stressors, it will put into play a variety of harmful responses which over the long term can literally kill you.
For example, Marcus has a high level of stress in his personal and professional life but he wants to lose weight effortlessly. He decides to employ a 16/8 fasting strategy (meaning he fasts for 16 hours and eats in an 8 hour window). While initially he gets great results, he hasn’t addressed the root cause of his weight gain, which is stress. (Stress can independently cause weight gain and health problems, possibly due to hormonal mechanisms.) A year later Marcus has not only stopped losing weight, he also finds that his favorite suit no longer fits. What’s worse, routine blood tests come back with some serious red flags, sparking alarm from his doctor.
Marcus would be well served by finding ways to reduce stress levels. He could cut back on work hours, incorporate daily relaxation techniques such as box breathing or Headspace, spend more time with family in nature, reduce the intensity of workouts, or he might even consider hiring a good therapist or personal coach! There is not one right way to reduce stress, it is a matter of doing what works for you (and please don’t tell me that what works for you is to go through a case of beer on Thursdays, we can have that conversation in person if you wish).
It’s not that the fasting has CAUSED the weight gain, but it is the combination of high stress levels alongside the organism feeling deprived of proper sustenance that has sent it into “fight for my life” aka gain weight and skyrocket cortisol levels mode. Marcus doesn’t actually need to fast to lose weight, but if he were to eat sensible whole foods when hungry and do some vigorous activity on most days, he would soon be fitting that fancy italian shirt he used to enjoy wearing.
Do these scenarios ring true to you or are you sure I’ve gotten it all wrong? In either case you may be right! I’d love to chat. Book an appointment with me at https://app.acuityscheduling.com/schedule.php?owner=13876588