In a world of information overload, we are constantly inundated with nutrition advice coming from all directions, most of which is conflicting, confusing, and contradicting. As a registered dietitian, it's up to me to weed through the hype, dig up the research, and uncover the truth.
Today's nutrition investigation is on Intermittent Fasting. Gaining popularity thanks to celebrities likes Hugh Jackman, Jimmy Kimmel, Jennifer Lopez, and Beyonce, it's time to set the story straight: Is Intermittent Fasting (IF) a safe and effective health intervention, or just another fleeting fad? Read on to discover the hard and fast truth behind IF.
Fasting regimes come in all shapes and sizes...
The concept of IF was sparked by an assortment of theories. Some propose that long bouts of fasting more closely resemble the eating patterns of our fellow mammalian species as well as the typical meal frequency of our human ancestors during hunting and gathering eras. Others argue that time-restricted feeding helps synchronize our eating patterns with our biological circadian rhythm. Longevity researchers suggest IF serves as a mild acute stressor, or "fire drill", conditioning the body to grow stronger and more resilient in anticipation for future stressors. Another theory is that IF creates ketosis, a state in which the body has fully exhausted its carbohydrate sources, and is forced to use fat as fuel.
While proponents of IF tout its ability to support weight loss, reduce the risk of cardiovascular disease, type 2 diabetes, Alzheimer's, and cancer, it's important to take an objective look at the research before you go starving yourself.
Though limited, there are in fact scientific studies that support the above theories. The critical question becomes, how strong is the evidence? The answer: pretty weak. Here's why…
In order to draw a definitive conclusion about IF, additional human research is required, using larger sample sizes, better research practices, and a longer duration of data collection. The research methodology needs to be designed in a manner that specifically isolates "fasting" as the experimental variable. It's still unclear whether the weight loss observed using IF in preliminary studies is specifically due to time restricted feeding, or if it's an indirect result of the caloric restriction that naturally accompanies IF.
The case for Intermittent Fasting has been analyzed from all angles. Here are the pros and cons to consider…
The Cons of IF
On a more positive note, there is a valuable lesson to learn from IF, and that's the relationship between food and time. Today, eating has become a 'round-the-clock activity, snacking our way from one meal to the next. Gaining a better understanding of how your food choices, meal timing, and eating frequency interact can help guide you towards a healthier, more personalized eating pattern. Here's how:
When it comes to IF, the jury is still out. But rather than wait around for stronger and more conclusive evidence, take advantage of the strategies already proven to optimize health and well-being: Eat real food. Sleep. Hydrate. Move. Relax. And, be mindful. Not only is this formula logical, practical and enjoyable, it's also effective and science-backed. Case closed!
Lindsey Kane is a Registered Dietitian from Philadelphia. For more nutrition tips and recipes, visit her blog biteforchange.com.