Should you only eat one meal a day?
IMAGINE if you only needed to worry about food once a day?
No more snacks, or planning lunch or worrying about what you were going to eat all day. All you need to consider is eating whatever you want or feel like, once a day.
Such is the proposal by a British doctor, Dr Van Tulleken who claims that taking intermittent fasting to the extreme and eating as infrequently as once a day is an effective and efficient way to diet.
So what are the pros and cons of this approach, should anyone actually want to only eat one meal a day?
1. Fasting has its benefits
There is no doubt that intermittent fasting has proven physiological benefits for the body. It helps to reduce inflammation, it appears to reset a number of hormones involved in fat metabolism and is associated with small amounts of weight loss in short term studies.
What is not known is the best type of fasting to achieve these results - is it shorter periods of fasting, longer overnight fasting or occasional fasts in which calorie intake is significantly reduced for a day every so often?
Until we know these specifics any proposed fasting regimen is generally a stab in the dark with hopes for the best.
2. Makes dieting easy
There is no doubt that one of the benefits of simple dietary rules is that they make plans a whole lot easier to follow. As soon as you simplify a diet to one meal, any meal, without any calorie or macronutrient restrictions, dieting suddenly becomes a whole lot easier. And ease of implementation is ultimately the key to long term dietary success.
3. Time efficient
Dietary adherence is dependent on a number of variables - having the foods on hand you need each and every day; planning; shopping; cooking food prep - actions that take a whole lot of time and time we often do not have.
Consuming only one meal a day, any meal you choose frees up significant amounts of time.
4. No calorie restriction
Successful long term weight loss requires calorie and macronutrient manipulation; regular adjustments to food intake and exercise and can be a technical process especially when you have relatively large amounts of weight to lose.
A dietary approach that does not require any specific dietary intervention other than to limit the number of eating occasions basically means dieters can eat what they like which is very attractive for individuals who love to be able to eat whatever they like and still potentially lose weight.
1. Issues for metabolic rate long term
The most significant issue likely associated with a one meal per day approach are the long term metabolic effects. When we begin a new weight loss regimen, it would not really matter what diet we followed, as long as we stuck to it.
Over time though calorie restriction results in reductions in metabolic rate, as muscle mass is broken down to fuel the basic energy systems. This means that over time we need fewer and fewer calories to fuel the body.
While a one meal a day approach may support easy weight loss initially, long term it is unlikely to support weight loss or weight maintenance.
2. People like to eat
Perhaps the most glaringly obvious issue with eating less frequently is that we are forgetting that people like to eat and in general have difficulties in controlling calorie intake when they are eating three times a day let alone once.
For the individuals not interested in food, eating less frequently may be a useful approach but this is unlikely to suit the average person.
3. Hunger management
Extreme hunger will be inevitable on a diet that limits eating occasions. While those with strong will power may be able to severely restrict calories for short periods of time, when they are experiencing constant hunger day in, day out, it will become more and more difficult to maintain this dieting approach.
4. Potential for overeating
Extreme hunger also tends to be a recipe for disaster when it comes to overeating. You will be familiar with the scenario in which periods of extreme dieting are closely followed by periods of extreme overeating. Limiting eating occasions which leads to periods of binge eating is not an ideal long term.
5. No long term evidence
As is the case with many of these new fasting approaches, long term evidence is lacking about its effectiveness. This means a one meal per day approach may sound like a useful weight loss option, but we really do not know if it works, if it works long term and who it may work for.
Until we know this, you are much better to stick to know what we do know works which is simply eating less than we need each day, and moving more.