Recently one of my clients asked me what exactly is a calorie restriction and how it works. So buckle up because in this article I will explain to you everything there is to know about calorie restriction, tips, and the benefits.
Does calorie restriction work? Calorie restriction is nothing else than reducing the number of calories in the diet to create a calorie deficit. It works by restricting calories and creating a cascade of metabolic changes that cause the body to use fat for energy, and over time, to lose weight.
But if that would be so easy, everyone would be walking around peeled with their abs displayed looking saucy all year round. But instead, over 80% of people who lost weight gain it back.
What Is Calorie Restriction
Have you’ve ever heard people talking about their new diet? They may say things like “I’m a vegan” or “I’m doing Paleo diet” or “Dr.X diet” or whatever. Recently I saw someone telling me they are on the calorie restriction diet and I almost fall off my chair.
Calorie restriction is not really a diet. It means reducing food intake to the point where our total daily calorie expenditure, including physical and non-physical activity, is bigger than our calorie intake (food that we eat). And by reducing the calorie intake and creating a calorie deficit, we lose weight.
And that will happen regardless if you’re on the ketogenic diet, paleo diet, or a plant-based diet. If you’re eating less food, you’re restricting calories.
But not only that.
Recent studies shows over and over that calorie restriction comes with tons of health-promoting benefits, as long as you do it for long enough.
Benefits of Calorie Restriction
I think the best way to illustrate to you the benefits of calorie restriction is by showing few studies that highlight all main key points. Bear in mind that those are the real-life examples of people, not the laboratory in vitro studies. Also if you want to dig deeper into the science, I’ve included all the resources where I pull off the studies. So feel free to put on your researcher hut on and learn more.
Calorie restriction improves mortality
The most obvious example you can see on the island called Okinawa near the Japanese mainland. According to statistics, Okinawan’s lifespan (the number of years you live) on average is around 83.8 years, with maximum numbers of 104.9 years (source).
The key takeaways
- On average, Okinawans have a 10–15% daily calorie deficit
- Diet is low on protein and rich in fresh vegetables, fruits, potatoes, soy, and fish (source)
- Okinawans consume around 17% fewer calories than the average adult in Japan
- Okinawans consume around 40% less than the average adult in the United States
The oldest “study” on restricting calories was done in 1920 by Mikkel Hindhede, a Danish physician and nutritionist. This study was actually done During World War 1 in 1917, but it was only published in 1920. This is one of those studies where you wouldn’t be able to do today because people didn’t choose to do it voluntarily. They were forced (source).
The key takeaways
- Documented 34% reduction in death rates in Danish men and women
- The main foods included whole-grain cereals, vegetables, and milk
Calorie restriction improves insulin sensitivity
Insulin sensitivity is nothing else than your efficiency of insulin to transport glucose away from blood to the rest of the body. High insulin sensitivity means less insulin is required to do the job. Poor insulin sensitivity means more insulin is required.
The key takeaways
- 40% improvement of insulin sensitivity after 6 months of 25% calorie restriction (source)
- Calorie restriction by diet alone or with exercise is enough to reverse insulin resistance (source)
Calorie restriction improves weight loss
Calorie restriction doesn’t always mean you have to eat less food. It can also means that you move more that usual. And by adding extra exercise in any form, you increase your energy expenditure, without changing your diet.
In either way, a 1-year study done at Washington University documented two groups. 20% of reduced calorie intake group one, and 20% of increased physical activity group two (source).
The key takeaways
- All of the people reduced weight and calorie restriction and exercise were equally effective
Of course, you can only imagine that with lower body weight, improved insulin sensitivity, and improved longevity there will be a dozen other indirect psychological as well as physiological benefits.
Can You Lose Weight Just by Restricting Calories?
Restricting calories is enough to trigger body to lose weight. The key element is the time and consistency. For weight loss to happen, it does takes time. So the best approach would be to not focus on which diet is better, but how you can sustain eating fewer calories.
Because if it doesn’t matter what diet you’re on, then is much better to find ways to maintain a healthy lifestyle while being in a calorie deficit.
Those would include things like:
- Managing the stress levels without eating. If you use food to reduce the stress you can have a never-ending loop of losing and gaining weight. Stress eaters need to find different methods to regulate their emotions and stress. Increasing physical activity, social interactions, getting a dog, traveling, and hobbies are all effective ways to reduce stress without using food.
- Trying occasional intermittent fasting to improve hunger tolerance. Physical hunger is different than psychological hunger. People generally are afraid of feeling hungry. But the more often you reduce food intake, you will get used to hunger and can realize that hunger is not an emergency. To learn more on how to do calorie deficit without being hungry check out my article.
- Eating mindfully without distractions. The more you’re anchored to the moment and you’re not being distracted by watching TV, driving a car, or eating on the go, you will more likely eat less because you can listen to your body signals.
- Organizing the home and kitchen environment to support your goals. If food is in your house or your possession, sooner or later you will eat it. So mindful shopping and storing food that is not gonna trigger unwanted behaviors is the easiest way to succeed.
How To Start A Calorie Restriction Diet?
There are multiple ways to start a calorie restriction diet. In general, reducing calories from the total food you eat, adding extra exercise, or both. Some of the best strategies include mindful eating, using a food plate as portion control, use a hand-size guide, or count calories.
There are no better or worse ways to eat less food. It’s all about preferences. Just like when choosing the color for the car you’re buying. Regardless of which color you decide, the car will still drive and do its work.
Things to consider before you choose your method
- People are not robots. Counting calories and meticulously measuring the food portions may be doable for the week or month. But for the long haul, deciding whenever I’m gonna eat my favorite meal based on the amount of fat or carbs it has is not sustainable.
- People are not spreadsheets. With some of the more advanced approaches like calorie counting you need to know exactly what you eat on the daily basis, make small adjustments, and track those adjustments (even as small as 50-100 calories). That is one spoon of peanut butter or olive oil. If you’re not committed to counting all of this, it may be hard for you to work otherwise.
- People are different. A 20-year old dude from YouTube who plays video games all day has different responsibilities in life comparing to a 35-year old single mom who is juggling 2 full-time jobs and looking after her sick mom.
- People have their own limitations. Things like allergies, food intolerance, aging, GI health, muscle and joint pain, illness, and more. Those limitations are what make us unique. That’s why choosing the calorie restriction method should be seen as an individual, not one-size-fits-all.
So when you choose to start a calorie restriction, you need to look at your lifestyle first, not what is most effective. Here is the list of how you can get started doing calorie deficit.
Mindful eating is about being present in the moment and focusing on how you eat, rather than what you eat. What you eat is important but how you eat is often forgotten and ignored. This include thing like:
- Eating slowly
- Eating when you’re physically hungry
- Eating till you feel no longer hungry
- Eating without distractions
Using Plates as Portion Reference
Using plates is a popular way to have a consistent reference point of what you eat. It works simply by dividing your plate in 3-4 groups and fill those spaces with the food you want. Things to consider:
- It’s easy
- It can be done by anyone (vegan, paleo, keto)
- It gives you the same reference with each meal
- It can be adjusted anytime
Using Hand-size as Portion Reference
Similar to plate reference, you can use your hand as a guide. The thickness of your palm is the protein portion. The full fist is the number of non-starchy veggies. A handful is for starch, and a thumb is for healthy fats.
- It’s easy and portable
- It can be done by anyone (vegan, paleo, keto)
- It gives you the same reference with each meal, regardless of the place you eat
Counting calories is the most popular and known method. It is the most accurate, but at the same time, it requires so much more work. You need to know your specific goals, calorie needs, and calories in each food. And frankly, the number of calories in foods may vary significantly, depending on many factors.
- Its most precise
- It’s done by professional athletes and actors to achieve desired weight fast
- It can get you very lean
How much weight can you lose with calorie restriction?
On average, you can lose between 1-3 pounds per week on a well-balanced calorie restriction plan. The amount of weight loss depends on things like age, gender, physical activity, lean body mass, total calorie intake, and other things that indirectly affect our food choices like stress and energy levels.
Is it better to fast or restrict calories?
In general, it doesn’t matter if you gonna be doing fasting or typical calorie restriction. The overall results come from being able to sustain long enough in a calorie deficit, and how each person is gonna do this will only depend on the preferences and lifestyle of the individual.
In summary, a calorie restriction diet is nothing else than just reducing your calorie intake. It can be as simple as skipping a meal, not eating after 6 pm, counting calories, eating slowly, or all of the above. In the end, the most important thing about calorie restriction is your ability to do it long-term.