Interest in the health benefits of fasting continues to grow as evidence builds to show the significant health and weight benefits associated with actively restricting our kilojoule intake on a regular basis. While this may all sound great in theory, the truth is that eating far, far less than we usually do is easier said than done. So, here are some ways you can get the benefits of eating less without needing to resort to full blown starvation.
Fasting is not a new concept. In fact, as early as the 1930’s saw the first scientific studies published showing lab rats increased their lifespan without becoming malnourished when feed a restricted kilojoule diet. More recently in the 1980’s studies of primates again reported these benefits along with lower rates of heart disease, cancer and longer lives in 50% of the chimps studied. Fast forward a few more years and studies specifically examining the metabolic benefits of fasting in humans gained interest and the commercial diets utilising this approach quickly followed.
Scientists have now identified that the metabolic benefits of regular fasting are explained by a family of proteins called the ‘sirtuins’ which appear to become activated when kilojoules are restricted (they are also activated when phenols from red wine and berries are consumed). These proteins are involved in a number of processes that keep the cells healthy, and long term healthy cells equates to less disease and potentially longer lives.
One of the initial diets to commercially target this scientific finding was the 5:2 Diet authored by British scientist Dr. Michael Mosely. The 5:2 Diet incorporates 2 non-consecutive days of very low kilojoule eating, just 2000-2500 kilojoules or ¼ of your regular calorie intake, followed by 5 days of regular, normal, non-restrictive eating. Interest in this approach has been wide and significant and while early results show some positive results when it comes to some weight loss and improved cholesterol and glucose levels, long term data on humans linking this approach to extra years lived is theoretical only.
So, since it sounds easy why not try it and cut right back on your food just 2 days each week and shed the kilos? In theory yes but in reality it may not be so easy for everyone.
2000-2500kJ diets mean that you will not be eating very much. For example, 2000-2500kJ spread over 2 meals equates to 1 poached egg on a small slice of wholegrain toast, a piccolo coffee in one meal and just 80-100g fish and vegetables or salad in the other. For non-eaters, such as busy businessmen or shift workers, this may not seem that extreme but for the average person, who tends to eat several times a day, such an enormous shift in eating habits may not prove that easy, particularly in social situations.
The second issue that can present when individuals adopt diets that are restrictive in nature is that psychologically it can prime us to think about food more and more. In this context, the simple act of aggressively restricting calories, especially after a lifetime of being ‘on’ and ‘off’ various diets, triggers the deeply entrenched thoughts that accompany the start of yet another diet. In this instance, the mere notion of being restricted, even for a very short period of time if enough to drive individuals to think about food, or rather the lack of it more and more, makes it almost impossible to maintain long term.
Another crucial point when considering including a regular fast in your weekly dietary regime is what your energy demands are like. If you sit down in front of a computer for many hours each day, and are not overly interested in food, cutting back for a couple of days is unlikely to cause any major issues. On the other hand, if you are a busy mum with 3 kids and you go to the gym every day, chances are cutting your calories back that much when your energy demands are high may leave you feeling tired, irritable and battling extreme hunger and cravings, even if it is just for a day in total.
Indeed a far easier and more sustainable approach may be to get into the habit of actively limiting your food intake on one day each week. Rather than complete starvation and skipping meals, simply enjoying a light breakfast of fruit or yoghurt, lunch of a light salad and dinner of soup or a white fish and vegetables will slash your kilojoules back to just 3000 or less without you really noticing. Another option is to simply skip dinner every so often. Chances are you do not always need it and it appears an extended period without is all the body needs to give it a metabolic kick start every so often.