Calorie Restriction: A Comprehensive Diet Plan Guide

Calorie restriction is a popular dieting method for those looking to lose weight and improve their health. The diet involves reducing your daily calorie intake by a certain percentage, typically ranging from 15% to 40%, while still meeting your essential nutrient requirements. This approach has been shown to be effective in supporting weight loss and improving cardiometabolic health markers, longevity, and cognitive function.

The key principle of a calorie-restricted diet is to ensure that your calorie intake is lower than your energy expenditure, creating a calorie deficit. This can be achieved by reducing your daily calorie intake, increasing physical activity, or a combination of both. It is important to note that the number of calories you need depends on various factors, including physical activity level, gender, age, weight loss goals, and overall health.

When following a calorie-restricted diet, it is crucial to focus on consuming nutrient-dense foods such as vegetables, fruits, nuts, lean meats, and whole grains, while limiting high-calorie, processed foods that are low in nutrients. Additionally, it is important to consult with a healthcare professional or dietitian to ensure that your nutrient requirements are met and to prevent potential side effects.

Calorie restriction has been a popular topic of research, with studies suggesting that it may increase longevity and reduce the risk of age-related diseases. While the impact of calorie restriction on human longevity is yet to be definitively proven, the available evidence suggests that it can lead to a healthier and possibly longer life.

Calorie-restricted diets: vegetables, fruits, nuts, eggs, dairy, meat, and whole grains

Calorie-restricted diets are a great way to lose weight and keep it off. The key is to ensure that your calorie intake is lower than your energy expenditure. A reduction of just 15% of your calorie intake can slow ageing and cause significant weight loss.

A calorie-restricted diet will consist mostly of vegetables, low-fat dairy, lean meat, fish, berries, eggs, fruits, nuts, whole grains, and legumes. These foods are low in calories and have a satiating effect.

• 2 hard-boiled eggs
• 1 medium banana
• Cottage cheese (1/2 cup)
• Roasted chicken breast (3.5 oz)
• 1 medium sweet potato
• Chopped salad blend (2.9 oz)
• Low-fat Greek yogurt (3.5 oz)
• Almonds (1 oz)
• Wild salmon (2.9 oz, cooked)
• Kale (1 cup, cooked)

This meal plan provides approximately 996 calories and will help preserve lean mass while on a diet. Season your meals with herbs, spices, or pickles for extra flavor.

While you may lose weight by limiting your intake to 1,000 calories a day, this may be too few calories and could place you at risk of nutritional deficiencies. Men should not eat fewer than 1,500 calories a day, and women should not eat less than 1,200 calories. Consult with your doctor before starting any calorie-restricted diet.

Intermittent fasting: alternate-day fasting, whole-day fasting, and time-restricted feeding

Intermittent fasting is a dietary approach that involves periods of either no food or very low calories and periods of unrestricted eating. It is based on choosing regular time periods to eat and fast. For instance, you might try eating only during an eight-hour period each day and fast for the remainder. Or you might choose to eat only one meal a day two days a week.

There are several types of intermittent fasting:

Alternate-day fasting

There are several variations of the alternate-day fasting plan, which involves fasting every other day. For some people, this means a complete avoidance of solid foods on fasting days, while others allow up to 500 calories. On feeding days, people often choose to eat as much as they want. This is an extreme form of intermittent fasting and may not be suitable for beginners.

Whole-day fasting

The 5:2 diet allows unrestricted eating for five days of the week and restricts calorie intake to 400-500 calories on the other two days. Typically, people separate their fasting days in the week, for example, fasting on a Monday and Thursday and eating regularly on the other days.

Time-restricted feeding

For this approach, a person only eats within a specific time frame and fasts for the remaining hours of the day. For example, between 8 a.m. and 3 p.m. There are various versions of this, such as the 16:8 diet, which involves fasting for 16 hours and leaving an 8-hour eating window.

Intermittent fasting may offer benefits such as fat loss, better health, and increased longevity. However, it may not be suitable for everyone, and it is important to consult a healthcare professional before starting any new diet plan.

Weight loss: create a calorie deficit, eat fibre-rich foods, and increase physical activity

Calorie-restricted diets are an effective way to lose weight and keep the pounds off. The key is to ensure that your calorie intake is lower than your energy expenditure. This can be achieved by eating fewer calories, increasing physical activity, or a combination of both. A safe and healthy calorie deficit is around 500 calories per day, resulting in a weight loss of about one pound per week.

To determine your calorie deficit, you must first calculate your daily calorie needs based on your age, sex, height, weight, and exercise habits. Once you know your maintenance calories, you can subtract 500 calories to determine your new daily target.

For example, if you need 2,000 calories per day to maintain your weight, eating 1,500 calories per day will create a 500-calorie deficit. Alternatively, you can burn an extra 500 calories through exercise, or a combination of the two methods.

It is important to note that food quality matters during a calorie-restricted diet. Focus on eating whole, nutrient-dense foods such as vegetables, low-fat dairy, lean meats, fish, berries, and eggs. These foods are low in calories and have a satiating effect, helping you feel fuller for longer.

In addition to calorie restriction, increasing your physical activity can further enhance weight loss. Aim for at least 150 minutes of moderate-intensity aerobic activity per week, such as brisk walking, or 75 minutes of vigorous-intensity activity, such as running. Strength training at least twice a week can also promote weight loss and improve overall health.

Finally, incorporating fibre-rich foods into your diet can aid in weight loss. Fibre helps promote a healthy weight by increasing feelings of fullness and reducing calorie absorption. Aim for at least 14 grams of fibre for every 1,000 calories consumed. Examples of high-fibre foods include kidney beans, berries, cruciferous vegetables, oats, chia seeds, and avocados.

Cardiometabolic health: lower blood pressure, improve glucose control, and reduce cholesterol

This diet plan is aimed at improving cardiometabolic health by lowering blood pressure, improving glucose control, and reducing cholesterol. It is important to note that before starting any diet plan, it is recommended to consult with a doctor or a certified nutritionist to ensure that the plan is tailored to individual needs and health status.

Calorie Restriction Diet

Calorie restriction is a dietary pattern that involves reducing average daily calorie intake by 15%-30% without compromising the intake of essential nutrients. This approach has been shown to be effective in slowing aging, causing significant weight loss, and improving cardiometabolic health. It is important to note that the key to a successful calorie-restricted diet is to ensure that calorie intake is lower than energy expenditure.

Improving Cardiometabolic Health

Lowering Blood Pressure

To lower blood pressure, it is recommended to include the following in the diet:

• Increase plant stanols and sterols intake: Aim for 2 grams per day, found in whole grains, nuts, legumes, and oils like olive oil and avocado oil.
• Limit salt intake: Aim for no more than 2,300 milligrams of sodium per day, which is about 1 teaspoon of salt. Choose low-salt or no-added-salt foods and seasonings.
• Limit alcohol consumption: If drinking, limit to no more than 2 drinks per day for men and 1 drink per day for women.

Improving Glucose Control

To improve glucose control and reduce the risk of diabetes, it is recommended to:

• Choose healthier fats: Limit total fat and saturated fat intake. No more than 25%-35% of daily calories should come from dietary fats, and less than 7% from saturated fat. Opt for lean meats, nuts, and unsaturated oils like canola, olive, and safflower oils.
• Limit foods with cholesterol: Aim for less than 200 mg of cholesterol per day. Cholesterol is found in animal-based foods such as liver, egg yolks, shrimp, and whole milk dairy products.
• Increase soluble fiber intake: Aim for 10-25 grams per day, found in whole-grain cereals like oatmeal and oat bran, fruits like apples and bananas, and legumes like kidney beans and lentils.
• Eat plenty of fruits and vegetables: These are important sources of vitamins, fiber, and other nutrients.

Reducing Cholesterol

In addition to the above recommendations, the following can help reduce cholesterol levels:

Increase omega-3 fatty acids intake: Omega-3 fatty acids can lower LDL ("bad") cholesterol and triglyceride levels, and help control blood pressure. Include fish like salmon, tuna, and mackerel in your diet at least twice a week. Plant sources like walnuts, flaxseed, chia seeds, and certain oils are also good sources but contain smaller amounts of omega-3 acids.

Sample 1,000-Calorie Meal Plan

• Breakfast: 2 hard-boiled eggs (120 calories), 1 medium banana (105 calories)
• Mid-Morning Snack: 1/2 cup cottage cheese (90 calories)
• Lunch: 3.5 oz roasted chicken breast (107 calories), 1 medium sweet potato (115 calories), 2.9 oz chopped salad blend (25 calories)
• Afternoon Snack: 3.5 oz low-fat Greek yogurt (73 calories)
• Dinner: 2.9 oz wild salmon (155 calories), 1 cup cooked kale (42 calories)

Improving cardiometabolic health through dietary changes is a gradual process, and it is important to be consistent and patient. It is also essential to monitor your health and adjust the diet plan as needed with the guidance of a healthcare professional.

Longevity: reduce DNA damage, increase autophagic mediators, and improve core body temperature

Calorie restriction diets have been shown to have a wide range of health benefits, including reducing DNA damage, increasing autophagic mediators, and improving core body temperature, all of which can contribute to longevity. Here are some ways in which you can incorporate calorie restriction into your diet plan to promote longevity:

Reduce DNA damage

Calorie restriction has been found to improve health and reduce the incidence of cancer in multiple organisms, including mice. A study on mice showed that short-term calorie restriction enhanced DNA repair by non-homologous end joining. This type of DNA repair pathway is essential in the aging process as it repairs the most severe type of lesion that can lead to genomic rearrangements.

Increase autophagic mediators

Autophagy is a conserved housekeeping mechanism that helps cells recycle exhausted materials and dispose of injured organelles. Calorie restriction and intermittent fasting have been shown to induce adaptive autophagy and increase longevity in eukaryotic cells. However, prolonged calorie restriction with excessive autophagic response can be harmful and lead to autophagic cell death.

Improve core body temperature

Long-term calorie restriction has been found to lower core body temperature in humans. A study on healthy, weight-stable individuals consuming a calorie-restricted diet showed a sustained reduction in mean 24-hour, daytime, and nighttime core body temperatures. This reduction in body temperature is similar to that found in calorie-restricted rodents and monkeys and may contribute to the anti-aging effects of calorie restriction.

• 2 hard-boiled eggs
• 1 medium banana
• Cottage cheese (1/2 cup)
• Roasted chicken breast (3.5 oz)
• 1 medium sweet potato
• Chopped salad blend (2.9 oz)
• Low-fat Greek yogurt (3.5 oz)
• Almonds (1 oz)
• Wild salmon (2.9 oz, cooked)
• Kale (1 cup, cooked)

Please note that while a calorie-restricted diet can have health benefits, it is important to ensure that you are still consuming adequate nutrients. Consult with your doctor or a registered dietitian before starting any new diet plan.

Frequently asked questions