Intermittent fasting and fat loss: how and why?
Intermittent fasting has been a popular topic of discussion lately with a wide variety of scientific and ‘less-scientific’ perspectives being exchanged. The majority of the discussion so far has been related to anecdotal evidence, and its easy to see that the discussion hasn’t been enlightening for most people: should you try intermittent fasting? What are the benefits, how, and for whom is it appropriate? This article will give you a brief guide to Intermittent fasting, or IF, and whether it is an appropriate weight-loss diet for you.
What is Intermittent Fasting?
Intermittent fasting is a dieting method where fasting and eating periods are alternated over pre-set time periods. This takes many forms, with some practitioners of IF having designated “fasting” days (either 1-on, 1-off or pre-set during the week), but the most common application is the feeding window. This usually means a period of 12-16 hours of fasting and 4-8 hours of feeding each day. We take this to be the quintessential method of using IF in recent years, and it is the most theoretically effective since it reduces overall feeding time compared to fasting time, combatting the possibility of binging (unlike 1-on, 1-off fasting).
The arguments for Intermittent fasting primarily rely on two benefits: First, the suggestion that fasting is a naturally superior approach with positive effects on a variety of health markers. Secondly, the reduced feeding time during the day makes it much more difficult to eat enough calories to maintain or gain weight: it isn’t as easy as you might think to eat 2000 calories in 4 hours! As ever, if a diet reliably produces a caloric deficit, then it is going to cause fat loss.
Isagenix’ own diet structure is based around intermittent fasting, with a focus on daily fasting with the addition of meal-replacement nutrition drinks. These products provide nutritional support without breaking the fast and contribute to accelerated weight loss. This makes the Isagenix diet a more effective approach to fasting days, which can increase weekly weight loss by as much as pound.
Does it work: can IF cause better weight loss?
The important thing to remember is that weight loss is the result of a simple mathematical comparison between your calories consumed and calories expended. Whilst it Is difficult to get an accurate fix on the values on either side of this equation, it is possible to come close and weight loss is possible for both intermittent fasting and any other dietary prescription. The important thing to remember is that many IF exponents compare low-calorie fasting diets with un-restricted diets to suggest that IF is superior. Obviously, the important question is whether a diet consisting of the same foods would increase weight loss if the consumption of foods was equalised across the two feeding periods. The question, then, is whether the same 1800 calories would have the same weight-loss effect if consumed over 4, or 24, hours.
The answer is possibly – the research on the subject suggests that there are some possible benefits to body composition and a variety of health markers. The research doesn’t tie this directly to fasting being a more “natural” approach to dieting, but there are a number of things to consider that make intermittent fasting a plausible and effective method of improving weight loss, and adherence:
- Satiety: a 4-hour feeding period is not enough time to considerably over-feed without conscious effort. Eating 1000 calories at the start of the feeding window will likely reduce sensations of hunger for a number of hours. It is easier, in this sense, to restrict caloric intake.
- Absorption: when consuming large quantities of food in a short space of time, there is a threshold for how much the body is able to absorb. When consuming large or excessive amounts of food, we have to consider the real possibility that digestion may not be efficient enough to extract all of the calories ingested – especially when consumed alongside large quantities of dietary fiber.
- Compensation: when consuming large quantities of food, the body compensates through thermic effect (the increase in temperature and metabolism in response to caloric energy). NEAT is the short name for non-exercise activity thermogenesis – the fidget-y movements that we perform throughout the day – and studies suggest that this can account for nearly 17% of the total daily calorie expenditure.
Side effects and concerns
Intermittent fasting may have some possible benefits for weight loss and health, but there are some concerns that should be taken into mind before you consider implementing this kind of dieting strategy. Side effects are not unheard of and there are certain populations that should avoid intermittent fasting due to the possibility of negative health effects.
A prime example of this is the case of those suffering from diabetes. Perhaps the greatest drawback of intermittent fasting is the fact that it causes sporadic, irregular blood sugar and digestive burdens. If you’re an athlete with multiple training sessions per day, or an individual that needs to maintain a healthy energy level throughout the day, intermittent fasting may not suit your needs as well as a consistent, regular-feeding diet with proper macronutrient and calorie balance.
Excessive fasting is a serious concern for all of us, however, with some people being more or less suited to extended periods of fasting. Depending on your individual physiology, it is possible to experience side effects such as nausea, light-headedness, headaches, constipation or dehydration as part of a fast. Ensure that you consume plenty of fluids during a fast and that the foods used in feeding are as high-quality as possible, with a balance of macro and micronutrients similar to any other diet.
Closing remarks: what’s the hype about?
Intermittent fasting has a small research base that suggests positive overall effects with a few simple conclusions that you can use to figure out how to use it, and if it suits your life. Firstly, a greater restriction of feeding hours will greatly benefit overall weight loss. It is difficult to only eat 4 hours per day, but this restriction plays into the positive effects associated with intermittent fasting, boosting fat loss.
Intermittent fasting is a reasonable dieting choice for anyone that struggles to maintain a regular healthy diet – either through weak will or a lack of nutritional know-how – and doesn’t have pre-existing metabolic conditions. The main benefit for intermittent fasting, however, is likely to be those people who struggle with snacking throughout the day: intermittent fasting makes this kind of insidious consumption impossible and restricts the calorie intake through increasing short-term satiety within feeding times. Experimenting with Intermittent fasting is highly recommended for weight loss, but individual differences are large and it’s important to see whether you experience side effects. If you’re trying intermittent fasting, be sure to hydrate properly and consume enough nutrients.