Caloric restriction: definitive guide

Diet and nutrition affect every process in our bodies. Energy is extracted, stored, and used. Micronutrients and macronutrients extracted from food contain building blocks of life, essential to our organism. There are significant benefits to health from calorie restriction and significant challenges. Reducing your calorie intake is worth it if done properly, over time and there may be ways to make it more sustainable.

Caloric restriction stands as a potent strategy for weight reduction and fat loss, concurrently exhibiting potential in extending lifespan and countering major chronic conditions like cancer, cardiovascular disease, cognitive decline, and metabolic disorders. Being slimmer tends to correlate with better health outcomes, mitigating risks associated with these “four horsemen of death.” However, caloric restriction without physical activity can lead to muscle loss alongside fat reduction, emphasizing the importance of coupling dietary moderation with regular exercise for preserving muscle mass and optimizing overall health benefits.

We know that the two main methods of altering our diet are Dietary Restriction (DR) and Caloric Restriction (CR). Both methods have their pros and cons and they may overlap to produce the best solution.

Dietary restriction can be combined with caloric restrictions or it may be separate.

What is the difference between DR and CR?

Whilst dietary restriction is all about excluding certain types of food from our diet, caloric restriction is all about cutting down on calories consumed without altering the sources. Both have pros and cons, but they can be used together to a great effect to improve our health.

While some studies have shown that CR can lead to improved health markers such as a lower risk of certain chronic diseases, the long-term effects of CR on lifespan and overall health in humans are not well understood.

Types of caloric restriction

Caloric restriction has been studied for its potential health benefits. Here are some of the most common ways of reducing calorie intake:

1. Intermittent fasting (IF): This is an eating pattern. Intermittent fasting involves alternating periods of calorie restriction with periods of regular or increased calorie intake. There are several types of IF, including alternate-day fasting, where individuals alternate between days of normal calorie intake and days of reduced calorie intake, and time-restricted eating, where individuals limit their daily eating window to a certain number of hours (e.g., 8 hours, which would mean 16 hours of not eating). Intermittent fasting is not strictly speaking a caloric restriction diet as the calories eaten might remain the same, however, fewer opportunities to consume food often lead to a lowering of overall calorie intake.
2. Long-term fasting (LTF): This involves reducing calorie intake significantly over a longer period of time, perhaps multiple days. This type of caloric restriction is often used for weight loss or as a treatment for certain medical conditions. Fasting is hard to maintain and can be dangerous.
3. Fasting-mimicking diet (FMD): This involves reducing calorie intake without eliminating food entirely. The FMD is a low-calorie, plant-based diet that is designed to mimic the physiological effects of fasting, such as promoting autophagy (cellular cleaning) and reducing inflammation, without the need to eliminate food completely.
4. Calorie restriction (CR): This involves reducing calorie intake by a set amount, usually 20-30% below baseline levels, on a daily basis, without altering food intake regularity. This is often used in animal studies to investigate the effects of caloric restriction on health and longevity.

It is important to note that any type of caloric restriction should be done in consultation with a healthcare professional or registered dietitian to ensure that it is safe and appropriate for individual needs and health status. Let common sense prevail, you don’t want to find yourself starved and malnourished. Moderation is key.

Caloric restriction and lifespan

Caloric restriction (CR) is the practice of reducing calorie intake while maintaining adequate nutrition, which has been shown to increase lifespan and improve health in various animal models, including mice and rats. Caloric restriction is studied in animals whose lifespan we can observe (it would not be good to study beings that live longer than humans):

1. In a study published in the journal Nature in 2009, researchers found that CR extended the lifespan of male and female mice by up to 30%, delayed the onset of age-related diseases, and improved their overall health. The researchers also found that CR improved cognitive function and reduced the incidence of tumors in the mice (1).
2. Another study published in the journal Aging Cell in 2017 found that CR increased the lifespan of male and female rats by up to 13%, improved their metabolic health, and reduced the incidence of age-related diseases. The researchers also found that CR improved the cognitive function of the rats (2).
3. A study published in the journal Aging in 2018 found that CR increased the lifespan of male and female mice by up to 45%, delayed the onset of age-related diseases, and improved their overall health. The researchers also found that CR reduced the incidence of cancer in the mice (3).

Despite the positive findings, there are also limitations and discussions surrounding the use of CR in animal models. Some of these limitations include:

1. The effects of CR may depend on the type of diet used. For example, a high-fat diet may offset the benefits of CR (4).
2. CR may not be effective in all species. For example, some studies have found that CR does not extend the lifespan of certain strains of mice (5).
3. CR may have negative effects on reproductive function and bone health, especially in females (6).
4. The mechanisms by which CR extends lifespan are not fully understood, and it is unclear whether the effects of CR in animal models can be translated to humans (7).

In conclusion, while CR has been shown to extend lifespan and improve health in various animal models, there are also limitations and discussions surrounding its use. Further research is needed to fully understand the mechanisms behind the effects of CR and its potential benefits and risks in humans.

Caloric restriction and insulin resistance

Insulin resistance is a measure by which your body’s cells don’t respond properly to the insulin that your body makes or the insulin you inject as a medication, high insulin resistance is bad and can lead to problems.

Caloric restriction (CR) has been shown to have beneficial effects on insulin resistance in various animal models and human studies. Here are some examples of studies that investigated the relationship between insulin resistance and reducing food intake:

1. In a study published in the Journal of Applied Physiology in 2009, researchers found that 16 weeks of CR improved insulin sensitivity in obese rats. The researchers also found that CR reduced body weight, plasma insulin, and leptin levels in the rats (8).
2. Another study published in the Journal of Gerontology in 2010 found that 6 months of CR improved insulin sensitivity in overweight and obese humans. The researchers also found that CR reduced body weight, body fat, and blood pressure in the participants (9).
3. A review published in the journal Ageing Research Reviews in 2015 examined the effects of CR on insulin resistance in various animal models and human studies. The review found that CR improved insulin sensitivity and glucose tolerance in rodents, non-human primates, and humans. The review also found that the beneficial effects of CR on insulin resistance may be mediated by changes in adipokine secretion, inflammation, and mitochondrial function (10).

These studies suggest that caloric restriction may have beneficial effects on insulin resistance in both animal models and humans. The mechanisms behind these effects are complex and likely involve multiple pathways.

Metabolism is a complex topic and more research is needed to fully understand the relationship between caloric restriction and insulin resistance. Overall it appears to be beneficial, but to determine the optimal duration and intensity of caloric restriction for improving metabolic health more research is needed and preferably on humans.

Caloric restriction and weight loss

Besides the effect on lifespan and insulin resistance, caloric restriction (CR) is a commonly used method for weight loss. It has been shown to have beneficial effects on fat loss in various studies.

1. A study published in the Journal of Clinical Endocrinology and Metabolism in 2007 found that CR led to significant weight loss and fat loss in obese individuals over a period of 6 months. The researchers also found that CR improved insulin sensitivity and reduced blood pressure in the participants (11).
2. Another study published in the Journal of the American Medical Association in 2016 found that 2 years of CR resulted in significant weight loss and fat loss in obese individuals. The researchers also found that CR improved cardiovascular risk factors and quality of life in the participants (12).
3. A review published in the Annual Review of Nutrition in 2017 examined the effects of CR on weight loss and fat loss in various animal models and human studies. The review found that CR led to significant weight loss and fat loss in rodents, non-human primates, and humans. The review also found that the beneficial effects of CR on weight loss and fat loss may be mediated by changes in adipokine secretion, inflammation, and mitochondrial function (13).

These studies suggest that caloric restriction may be an effective method for weight loss and fat loss in both obese and non-obese individuals. The beneficial effects of CR on weight loss and fat loss may be mediated by changes in various metabolic pathways, but more research is needed to fully understand these mechanisms and to determine the optimal duration and intensity of CR for weight loss.

Being in fasted state in general appears to be beneficial for weight loss for understandable reasons, caloris restrictions allow to reach that fasting state.

Caloric restrictions limitations and how to overcome them

Caloric restriction (CR) can have both physiological and psychological effects on individuals who try it. Some of the potential problems include the following:

1. Hunger: The most simple and straightforward thing everyone has experienced is hunger. If you attempt to lower your calorie intake, one of the most common side effects of CR is increased hunger and appetite, which can make it challenging to maintain a calorie-restricted diet. It can be managed.
2. Nutrient deficiencies: CR can lead to nutrient deficiencies if the diet is not carefully planned and balanced.
3. Fatigue: Some individuals may experience fatigue or low energy levels when starting a CR diet, which can make it difficult to maintain physical activity levels.
4. Mood changes: CR can lead to mood changes, including irritability, anxiety, and depression, in some individuals.
5. Eating disorders: Individuals with a history of eating disorders may be at higher risk for developing disordered eating behaviors when attempting CR.

Reduce calorie intake gradually

Reducing calorie intake can be challenging, especially for individuals who are used to consuming a high-calorie diet. However, the body can adapt to lower calorie intake over time, and individuals may find that their hunger levels decrease as they adjust to the new diet. It is important to note that CR should be done in a gradual and sustainable manner, and individuals should consult with a healthcare professional before starting a calorie-restricted diet to ensure that it is safe and appropriate for their individual needs.

It may take several weeks for individuals to adapt to a calorie-restricted diet, but the exact timeframe can vary depending on factors such as the individual’s starting calorie intake, body composition, and physical activity levels. It is important to approach CR as a long-term lifestyle change rather than a short-term diet, in order to achieve sustainable results and avoid potential negative side effects.

Overcoming hunger

There are several strategies that can help individuals offset the feeling of hunger and cravings during caloric restriction (CR) or other dietary approaches. Some of these strategies include:

1. Drinking water: Drinking plenty of water throughout the day can help reduce feelings of hunger and promote feelings of fullness. Aim to drink at least 8 cups of water per day, and more if you are physically active or live in a hot climate.
2. Chewing sugar-free gum: Chewing sugar-free gum can help reduce cravings and promote feelings of fullness. However, it is important to choose sugar-free gum to avoid adding extra calories to the diet.
3. Meditation and mindfulness: Practicing meditation and mindfulness techniques can help reduce stress and emotional eating, which can contribute to feelings of hunger and cravings. Try taking a few deep breaths or practicing a brief meditation session when you feel hungry or stressed.
4. Finding other ways to boost dopamine: Dopamine is a neurotransmitter that is associated with feelings of pleasure and reward and is often linked to food cravings. Finding other ways to boost dopamine levels, such as engaging in physical activity or hobbies, can help reduce cravings and promote feelings of satisfaction.
5. Positive thinking and self-talk: Reminding yourself of the benefits of CR, such as improved health and weight loss, can help reinforce positive thinking and reduce feelings of deprivation. Try repeating affirmations or positive statements to yourself when you feel hungry or tempted to eat.

It is important to note that hunger and cravings during CR are a normal part of the process, and individuals should not feel guilty or ashamed if they experience these feelings. It is entirely natural and completely understandable. Humanity only recently found a way to avoid food scarcity. It may take time and experimentation to find the right combination of strategies to manage hunger and cravings, and individuals should consult with a healthcare professional for guidance and support in developing a safe and effective weight loss plan.

Overcoming nutrient deficiencies from caloric restrictions

There are several strategies that can help individuals overcome nutrient deficiencies during caloric restriction (CR) or other dietary approaches. Some of these strategies include:

1. Testing for nutrient deficiencies: If you are concerned about nutrient deficiencies, it is a good idea to talk to your healthcare provider about testing for mineral and vitamin deficiencies. This can help you identify any specific nutrient deficiencies and develop a plan to address them.
2. Eating nutrient-dense foods: Eating a variety of nutrient-dense foods can help you meet your nutritional needs during CR. Focus on consuming foods that are rich in vitamins, minerals, fiber, and other essential nutrients, such as fruits, vegetables, whole grains, lean proteins, and healthy fats.
3. Taking supplements: If you are not able to meet your nutritional needs through diet alone, taking supplements can be an effective way to address nutrient deficiencies. Be sure to talk to your healthcare provider before taking any supplements, as some supplements can interact with medications or have side effects.
4. Consuming sources that contain electrolytes: Electrolytes are minerals that are essential for proper fluid balance and muscle function in the body. Consuming sources of electrolytes, such as sodium, potassium, magnesium, and calcium, can help prevent dehydration and electrolyte imbalances during CR. Good sources of electrolytes include leafy green vegetables, nuts and seeds, fish, poultry, and dairy products.

It is important to note that nutrient deficiencies can be a serious concern during CR, and individuals should work closely with a healthcare provider or registered dietitian to develop a safe and effective weight loss plan that meets their nutritional needs.

Meditation and mindfulness to enhance caloric restrictions

Meditation and mindfulness practices can be helpful tools for individuals who are trying to cut down on calorie intake and manage cravings and hunger. Meditation makes one more aware of their own body, which should not be underestimated as a method of improving one’s health. Here are some steps to get started with meditation and mindfulness:

1. Find a quiet space: Choose a quiet, comfortable space where you can sit or lie down without distractions.
2. Set a time limit: Start with a short meditation session, such as 5-10 minutes, and gradually increase the time as you become more comfortable with the practice.
3. Focus on your breath: Focus your attention on your breath, and try to notice the sensation of air moving in and out of your body. If your mind wanders, gently bring your attention back to your breath.
4. Practice mindfulness: When you are eating, try to focus your attention on the sensory experience of the food, such as the taste, texture, and aroma. Notice any thoughts or emotions that arise, but try not to judge or react to them.
5. Use guided meditations: There are many apps and websites that offer guided meditations and mindfulness exercises. These can be helpful for beginners who are learning how to meditate and experience mindfulness.
6. Be consistent: Like any skill, meditation, and mindfulness require practice and consistency to become effective. Try to practice daily, even if it is only for a few minutes at a time.

By incorporating meditation and mindfulness practices into your daily routine, you may be better able to manage hunger and cravings during caloric restriction and cultivate a greater sense of mindfulness and awareness in your daily life.

Finding other sources of dopamine to replace food intake

Dopamine is a neurotransmitter that is associated with feelings of pleasure and reward and is often linked to food cravings. Finding other ways to boost dopamine levels can be helpful in reducing food cravings and promoting feelings of satisfaction. Here are some cool ways to find dopamine:

1. Exercise: Physical activity, such as running, cycling, or dancing, can increase dopamine levels and promote feelings of pleasure and satisfaction.
2. Music: Listening to music that you enjoy can also increase dopamine levels and promote positive emotions.
3. Creative activities: Engaging in creative activities, such as painting, writing, or crafting, can also promote feelings of pleasure and satisfaction.
4. Social interaction: Spending time with friends and family or engaging in social activities can increase dopamine levels and promote positive emotions.
5. Achieving goals: Setting and achieving goals, whether they are personal or professional, can also increase dopamine levels and promote feelings of satisfaction and accomplishment.
6. Getting outside: Spending time in nature, whether it’s taking a hike or simply sitting outside in the sunshine, can also increase dopamine levels and promote positive emotions.

By incorporating these activities into your daily routine, you may be able to reduce food cravings and find alternative sources of pleasure and reward. However, it is important to note that while these activities can be helpful in managing cravings, they should not be used as a substitute for adequate nutrition and caloric intake.

Being mindful of possible mood swings due to CR

Lowering calorie intake through caloric restriction (CR) can sometimes result in mood changes and irritability, which can be challenging for both the individual and those around them. Here are some strategies that can help individuals overcome mood changes during CR and minimize the impact on those around them:

1. Practice self-care: Engage in activities that promote self-care and relaxation, such as taking a bath, practicing yoga or meditation, or listening to music. This can help reduce stress and promote positive emotions.
2. Communicate with others: Let your friends, family, and colleagues know that you are undergoing CR and may be experiencing mood changes or irritability. This can help them understand what you are going through and be more patient and supportive.
3. Keep a food diary: Keeping a food diary can help you identify any patterns between your mood changes and what you are eating. This can help you make adjustments to your diet to better manage your mood.
4. Stay hydrated: Dehydration can contribute to mood changes and irritability, so be sure to drink plenty of water and other non-caloric beverages throughout the day.
5. Get enough sleep: Lack of sleep can also contribute to mood changes and irritability, so be sure to prioritize getting enough sleep each night.
6. Practice gratitude and positive thinking: Remind yourself of the benefits of CR and focus on the positive aspects of your life. Practicing gratitude and positive thinking can help reduce stress and promote positive emotions.

It is important to remember that mood changes during CR are a normal part of the process, and that it is possible to manage them with the right strategies and support. By practicing self-care, communicating with others, and staying mindful of your own needs and the needs of those around you, you can successfully navigate the challenges of CR and achieve your weight loss goals.

Eating disorders and calorie restriction

Caloric restriction (CR) can potentially exacerbate or trigger symptoms of several eating disorders, including anorexia nervosa, bulimia nervosa, and binge eating disorder. These eating disorders involve a complex interplay of biological, psychological, and environmental factors, and may require specialized treatment and support.

Individuals who are undergoing CR and have a history of disordered eating should be vigilant for signs of relapse or worsening symptoms, such as:

1. Obsessive thoughts about food or weight
2. Preoccupation with body shape or size
3. Restricting food intake to the point of starvation
4. Engaging in binge eating or purging behaviors
5. Using diet pills, laxatives, or other weight-loss supplements
6. Experiencing significant distress or impairment in daily functioning due to eating-related concerns.

If you are concerned about the potential for CR to exacerbate or trigger symptoms of an eating disorder, it is important to talk to a healthcare professional who is experienced in treating eating disorders. This may include a primary care physician, a psychiatrist, a psychologist, or a registered dietitian who specializes in eating disorders.

A healthcare professional can help you assess your risk for developing an eating disorder or relapsing into a previous eating disorder, and provide guidance and support for managing these concerns while undergoing CR. It may also be helpful to work with a therapist or support group that specializes in eating disorders, as these resources can provide additional support and strategies for managing the complex challenges of disordered eating.