Nutritional biochemist Dr Libby Weaver on whether intermittent fasting is everything it’s claimed to be.
You don’t have to look very far to find someone who will tell you intermittent fasting is the answer to exceptional health and easy weight loss.
It’s no surprise then that people want to know if it’s everything it’s claimed to be and I’m often asked for my perspective on it. Like with all things, I will give you all sides of it so you can make a decision that’s right for you and your health.
There are different styles of intermittent fasting around at the moment. On some of them you’re encouraged to skip breakfast and narrow your eating window, while on others you are suggested to eat 500 calories a day for two days per week.
Let’s explore the latter.
If you’re restricting your calories to 500 on a day where you don’t have much on and where you don’t use your brain that much, maybe this is okay. But if it’s a day where you’re particularly busy and you’ve got a lot to get through, it might not be wise or even healthy to only eat 500 calories for that day. We forget that the brain uses a huge amount of energy to run so many functions in our body and also to make decisions and help us concentrate.
Also, when we restrict our caloric intake to below about 1200 calories per day, it’s very difficult, if not impossible, to meet our micronutrient needs—that’s all of our vitamins and minerals.
The importance of micronutrients
It’s the micronutrients that allow us to obtain the energy out of our food and help us to actually enjoy our days. Remember, when we’re exhausted, everything is more difficult. It’s harder to cook for ourselves, harder to exercise, harder to be patient with strangers and the people we love most in the world. Energy really matters.
And, of course, we need all the nutrients to drive the biochemical pathways in our body that allow everything to work incredibly well—everything from your liver and sex hormone balance to your adrenal function and digestion. None of it will work properly without adequate nourishment and enough food. So, if you do want to follow an intermittent fasting approach, it’s incredibly important to ensure that you focus on eating plenty of micronutrients when you’re not fasting so that your body gets what it needs.
The other thing to remember is that there is no quick fix when it comes to health or weight loss. If you’re looking for shortcuts, you’re going about it all wrong. Great health, and subsequent weight loss – if less body fat would physically benefit your health (some people will be healthier with increases in their levels of body fat) – comes from nourishing your body and your cells with whole, real food and supportive lifestyle choices.
Sustainable change happens over time as your body begins to respond to the support and the nourishment. What we know about diets and quick weight loss is that it’s generally not sustainable. Statistics tell us that around 80 per cent of people put the weight they lost back on, and often more, until the emotional reasons behind why someone is using excess food or too many poor quality food choices to cope, are addressed.
The mental side of fasting
Intermittent fasting is essentially still a diet. You’re still reading someone’s external philosophy and advice on food and following that. And you’re either on it or you’re off it.
One of the things that concerns me about any diet, is how the dieting mentality influences the way we speak to ourselves and how we feel about ourselves. Most people don’t respond well to rigidity around food. It tends to feed a cycle of feeling good when on a diet but not being able to keep it up and then feeling lousy about yourself and your perceived lack of ‘self-discipline’. This often then leads to throwing in the towel and going back to old habits because ‘what’s the point?’.
Yo-yoing between nourishing eating and living on junk is not good for our health.
A much more effective approach is to focus on eating for nourishment—so eating whole, real food—most of the time and allowing for some flexibility occasionally.
If you were truly in touch with your appetite (so putting aside emotional eating, for example, or other reasons why you might be eating more than your appetite asks of you), you would actually notice that there are days when you’re naturally not that hungry.
Think about summer when it’s really hot. You don’t want heavy, hot food; you tend towards light, cooling foods like salads. So, on a hot summer’s day, your caloric intake usually naturally declines. This tells us that we do have those natural ebbs and flows with our appetite and if we learn to trust our body, it will guide us.
The benefits of fasting
One of the principles in numerous styles of intermittent fasting is eating your evening meal as early as possible.
This can be a great concept to embrace as often as you can, as most people find they are more comfortable and sleep better the earlier they eat.
You might like to get organised on a weekend and prepare some dinner meals so you can eat close to arriving home, at least a few evenings each week.
All of this aside, I never want to put down anything that helps people.
So, if intermittent fasting is something that’s helping and working for you, then by all means continue with it. But just be aware that it is still a diet and check in with yourself whether this might be affecting the relationship you have with yourself and your body.
Dr Libby is a nutritional biochemist, bestselling author, speaker and founder of the plant-based supplement range Bio Blends. You can find out more about her books and courses at drlibby.com.