Do you want to lose pounds and wonder if you need to fast or follow a balanced diet plan? Intermittent fasting is one of the most popular trends in the world. It is also known as a 16:8 or 5:2 diet and is a relatively “modern” diet. But how effective is intermittent fasting in weight loss and does it outweigh a balanced diet?
What is intermittent fasting (IF)?
By intermittent fasting, we call the abstinence or limited consumption of food and drink for some hours up to days. It is a nutritional pattern that alternates feeding periods, without any calorie restriction, with fasting periods where either no food is consumed or very few calories throughout the day. It is used for weight loss, as well as for health.
What types of intermittent fasting are there?
There are various fasting protocols, such as fasting on alternate days, fasting all day or time-restricted feeding. The most popular methods are:
• Method 16:8 or time-restricted feeding
Limitation of feeding period to a predetermined interval of 8 hours in the day, for example from 13:00 to 21:00. The remaining 16 hours of the day, absolute fasting.
• Fasting on alternate days
Switching between days without restriction to eating, with days consisting of a meal that provides about 25% of the daily energy needs (~ 400-600 calories). The number of fasting days may vary.
• Method 5:2 or fasting all day
This method contains unlimited food on most days in a week and complete fasting or reduction of food 1-2 days a week. The protocol 5:2 supports fasting 2 non-consecutive days of the week (consumption of about 25% of daily energy needs ~ 400-600 calories) and the remaining 5 days unlimited food consumption.
Is there a benefit in weight loss with fasting?
Supporters of intermittent fasting believe that the stress, which is caused by intermittent fasting pattern, leads to an immune response that contributes to cell renewal and has positive changes in many markers and parameters such as triglyceride reduction, LDL cholesterol, arterial pressure, insulin resistance, fasting glucose, weight, fat mass etc.
A systematic review of 40 studies found that intermittent fasting was effective in weight loss, respectively, with a typical diet. In terms of body weight and body composition (fat, lean mass), there was no significant difference in the rate of loss between intermittent fasting and standard diet. With regard to those who drop out of the diet, the review did not find that fasting had a lower dropout rate and therefore was not necessarily easier to follow in relation to other weight loss protocols. Additionally, there was no difference in the appetite of the participants.
Other randomized controlled trials in obese individuals have not found that fasting is more effective in weight loss than daily calorie restriction as well as in parameters such as blood pressure, heart rate, fasting glucose and fasting insulin.
Things to consider in IF
One concern for those who follow the fasting model is that there may be over-eating in the days of non-fasting and so the calories lost during fasting are compensated. However, studies have not shown that this is true compared to other methods of weight loss.
The fasting diet is difficult for someone who is used to eat every few hours and have snacks between meals, while also it does not educate people. Even though, the percentage of weight loss between diets seems to be the same, nutritional education cannot be replaced as it is necessary to maintain weight loss.
Some people, either because of their medical history or medication, is forced to eat without extreme constraints or at regular intervals and should not follow the fasting pattern, like people with or on:
- Development, such as children and adolescents
- Pregnancy or breastfeeding
- Eating disorders unhealthy self-limitation (anorexia or bulimia nervosa)
- Using medication that requires food
Weight loss itself has many health benefits. The method of fasting is not less or more beneficial than conventional weight loss diets. For some people, it seems easier to be disciplined on certain days of the week without restricting food every day, but this protocol does not include nutritional training.