Intermittent fasting vs daily calorie restriction

As you probably know already, intermittent fasting (IF) has gained favour as an alternative regimen to daily caloric restriction (DCR). Fasting is shown to extend the lifespan of rats, and has been associated with metabolic benefits in humans, yet the results so far have been inconsistent. So, which regimen is best for healthy weight loss?

You know what it’s like! To think you’ll never have your fave food again. And to be on a diet forever. (Well, what seems like forever!) Every major religion, such as Christianity (Lent), Islam (Ramadan) and Judaism (Yom Kippur), has some element of fasting.

I was intrigued when a study looked at 13 trials between IF and DCR with matched calorie intakes. These articles were published from January 2000 until April 2022. Of the 13 studied, four were time restricted eating (TRE), one was fasting on alternate days, two were the 4:3 Diet and six were the 5:2 Diet.

Pros

• When fasting, you learn to feel hunger as a 0 or 1, which I rate as Ravenous in my Hunger-Fullness Log (524 KB). You can use this handy log to track your hunger by rating your feelings of hunger from 0 to 10 over the day. You’ll soon realise the times when you eat out of “mouth hunger”, not stomach hunger. 
• Fasting can be a terrific way to lower your weekly kilojoule (Calorie) intake. And with a greater insulin sensitivity, fasting is thought to be a superior regimen to limiting your calorie intake (if this study is to be believed!)
• With the alternate-day, 4:3 and 5:2 regimens, you only have to restrict your food intake for two or three days each week. You can eat your fave foods again!
• For many people, fasting is preferable than being on a “diet” forever.
• Fasting is ideal for people who can’t stick to a set diet (me included).
• It is ideal for people to retrain their taste buds and learn to eat right in the long term.
• By only fasting for only ONE day at a time, you don’t enter an extended famine. So your body’s energy-preservation tactics don’t kick into action.
• Fasting is a weight-loss diet option that does NOT involve calorie counting or eliminating certain foods.

Cons

• You may feel unbearable hunger on the fasting day. You may also feel a little cranky, tired and weak.
• Fasting days can interrupt normal family dinners or dinner invitations.
• You may overeat on the day after you fast. Understand this and minimise it. 

Read more HERE

The paper

“The Effects of Isocaloric Intermittent Fasting vs Daily Caloric Restriction on Weight Loss and Metabolic Risk Factors for Noncommunicable Chronic Diseases: A Systematic Review of Randomized Controlled or Comparative Trials.” You can read more at https://pubmed.ncbi.nlm.nih.gov/36126910/

 The bottom line

 The different fasting interventions produced similar beneficial effects for weight loss and chronic diseases such as heart disease, type 2 diabetes and various cancers. There is very limited evidence suggesting that fasting may be more effective than daily calorie restriction for fat loss and insulin sensitivity, but conclusions cannot be drawn based on the current evidence.

 It’s the same old, same old. More research is needed to fully explain what’s going on. There may be male/female differences operating, too. Many women find fasting too hard to stick with (men cope better for reasons that aren’t clear).