Three meals a day: Why I don't recommend fasting
So many diet experts are recommending fasting lately. If you've read my books, you know that I do not. Why?
Fasting helps with weight loss in some people, but not more so than other methods. Deliberately fasting and restricting feeding times can help some of us regulate our appetites, allow for fat burning, and also it can help regulate hormones that determine body composition.
If you stop fasting, however, you'll put the weight back on, just like any other diet regimen. The body does not like to starve. The brain, whose one job is to keep us alive, is vigilant against starvation. It has a whole resume full of tricks to get you to eat more, slow down, hoard fat, and burn fewer calories if it senses that starvation might be possible.
I don't believe that fasting is ideal, and I think it can be detrimental to anyone who has suffered from disordered eating or has had food restricted in the past.
Reasons why some of us do not benefit from fasting are numerous. Sometimes the cause of weight problems is a dysregulated appetite or a dysregulated metabolism. And some of us have a dysregulated sense of reward from food. In these cases, it will be hard to restrict food, or if food is restricted successfully, the 8-hour eating window becomes an 8-hour binge. The binge will upset leptin sensitivity, and also cause an insulin spike that will ensure that most of the food ingested during that 8-hour binge is stored as fat.
Especially for habitual dieters, or those of us who have suffered starvation or calorie restriction, the more often the body has had to do without enough food, the better it is at using starvation mode to store fat, increase food intake, and decrease energy expenditure. So, if you have dieted in the past and lost weight, fasting may quickly trigger your body's and brain's "starvation mode". You may find your appetite during your "eating window" voracious, so the recommendation to eat normally is impossible. You may find you get tired and slow down. You may also find that your brain becomes completely focused on food. Your body is protecting you from what it sees as an upcoming threat: lack of food.
In addition to triggering a finely tuned starvation response, intermittent fasting can cause some chemical imbalances that cause dysregulated eating. The two main problems intermittent fasting causes in this regard involve leptin and insulin.
Eating too little causes leptin to go too low, and so our appetite becomes fierce and our bodies lock down our fat stores. When we then gorge, or eat too much, we eat past the signals from our rising leptin, we eat well past fullness. And, this causes our cells to start ignoring leptin: our bodies still think they are hungry, and our fat doesn't come out of lockdown.
Eating a lot all at once causes insulin to spike. When insulin is high, fat cannot be burned. Insulin increases appetite and tells the body to store fat. Insulin is known as the storage hormone. When we overeat, most of the excess calories are stored as fat because of insulin. Also, high insulin levels cause insulin resistance, meaning our cells start to ignore insulin's call, and so they cannot absorb energy. Fat cells become insulin resistant last, so, when we are insulin resistant, many of us can have hungry bodies that store fat before the rest of us get fed. This is why bingers can gain weight, even if they only overeat while bingeing. Intermittent fasting can trigger binge eating or other eating disorders in those of us with a history o
Time between meals is a magic element that supports our other efforts to achieve or maintain a healthy body. But we have to use time in a way that does not alert our brains fears of starvation. Allowing time between meals does the following:
1. Regulates Leptin sensitivity and Leptin levels. Leptin is a substance the body makes in response to eating, higher leptin levels make us feel full and signal to our bodies that it is safe to burn fat. However, when we overeat or eat too often, our cells stop listening to leptin. They become leptin insensitive. Allowing time between meals helps our leptin levels to fall, allows us to become sensitive to leptin again, and so helps to regulate our appetite. When we are leptin insensitive, we can eat past fullness. Especially if we are very hungry. This is how fasting can backfire for some of us.
2. Supports Insulin Sensitivity. Insulin is secreted by the pancreas in response to blood glucose. Glucose is stored by our muscles and our cells and used for energy, but it is extremely toxic in the bloodstream. The body wants to get glucose out of the bloodstream and stored quickly. If our cells are full and have stopped listening to insulin, and our muscles are full as well, two things can happen. 1. Fat cells readily take up blood glucose and store it as fat, or, 2. our pancreas pumps out more and more insulin, to try to force our cells to take up more. Especially if we have fat cells that are insulin resistant, our pancreas can wear itself out trying to get the poisonous glucose out of our bloodstream. This is how diabetes gets started, it's also how we can store fat even though we rarely overeat, how we can feel hungry even though we've eaten enough.
So, it is true that time between meals is important. Time between meals allows insulin levels, blood sugar levels, and leptin levels to drop. Time between meals gives our pancreas a rest, and our appetite a chance to reset.
The solution is three meals a day and no eating in between. This used to be the universal rule. Mothers used to admonish their children not to snack or they'd, "ruin their dinner." Eating while walking around, at one's desk, driving, or doing anything else aside from sitting at a table at mealtime was considered rude.
Three meals a day is an almost universal ideal that most cultures, in one way or another, have abided by since the beginning of time. It's ancient wisdom at work.
How do we put this into play for ourselves? How do we harness the benefits of intermittent fasting, but avoid the problems that can arise for those of us who have had problems with disordered eating, or have had calories restricted?
We eat breakfast in the morning. We make sure we eat enough food to get us through til lunch. We eat lunch 4-5 hours after breakfast, and then we eat dinner 5 or 6 hours after lunch. And we eat nothing in between. Which means we go from dinner time to breakfast without eating. If we eat dinner at 6pm and then eat breakfast at 7 am, this creates a 13-hour fasting window during a time when our body is naturally programmed to slow down metabolism and digestion.
Personally, I have found that my body just takes longer to process food than it used to when I was younger. So, I try each day to eat a bigger breakfast and lunch, and small, early dinner. By eating dinner earlier, I increase fasting time without skipping a meal. By eating a smaller dinner, my body has an easier time processing food and I wake up with a better appetite.
I have also found that making sure I eat at least 50% of my daily caloric intake during breakfast and lunch calms my appetite down for the rest of the day. I don't have a mid-afternoon hungry horror strike, nor do I have a late afternoon energy drop. It is much, much easier for me to manage my appetite and avoid bingeing if I have eaten plenty earlier in the day. The brain gets the message that food is plentiful and shuts down not only the appetite, but the reward loop that makes us motivated towards, and constantly thinking about, food.
For millions of years people ate without much thought to dieting. No one was obese. The body knows what to do with food. If we learn what the signals are that tell our brain that starvation is possible, we can learn to avoid them, and then our appetites, our metabolisms, and our feelings of reward from food normalize. It starts with three meals a day of healthy, whole foods.
