What Is A Calorie Restricted Diet

Healthline Diet Score: 329 Out Of 5

Scripps Researchers Uncover What Could Make Calorie-Restricted Diets Effective

When trying to lose weight, creating a calorie deficit either by eating less or increasing physical activity is necessary.

Many people choose to follow a 1,500-calorie diet plan to jumpstart weight loss and control their food intake.

This article explains how to follow a 1,500-calorie diet, including foods to eat, foods to avoid and tips for healthy, long-term weight loss.


  • Nutrition quality: 2.5
  • Evidence based: 3

BOTTOM LINE: A balanced 1,500-calorie diet rich in nutritious foods fits the needs of many people who want to lose fat and improve health. Still, while 1,500 calories may be a good guideline for many people, it may not be enough for some.

Diets Followed For Medical Reasons

People’s dietary choices are sometimes affected by intolerance or allergy to certain types of food. There are also dietary patterns that might be recommended, prescribed or administered by medical professionals for people with specific medical needs.

Calorie Restriction And Fasting Diets: What Do We Know

You may have heard about calorie restriction and fasting diets and wondered why they’re getting so much attention in the news. Aren’t they just other terms for dieting to lose weight?

No, they’re not. Calorie restriction means reducing average daily caloric intake below what is typical or habitual, without malnutrition or deprivation of essential nutrients. In a fasting diet, a person does not eat at all or severely limits intake during certain times of the day, week, or month. A practical effect of a fasting diet may be fewer calories because there is less time for regular eating.

These eating patterns are being studied as possible ways to maintain good health and live longer. They are not temporary weight-loss plans. Interest in their potential health and aging benefits stems from decades of research with a variety of animals, including worms, crabs, snails, fruit flies, and rodents. In many experiments, calorie-restricted feeding delayed the onset of age-related disorders and, in some studies, extended lifespan.

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Very Low Calorie Diets Are Not Suitable For Most People

See a GP if you think a very low calorie diet may benefit you.

Very low calorie diets are not suitable if you are:

If a GP thinks a very low calorie diet might benefit you they should make sure:

  • the diet is nutritionally complete
  • the diet is followed for a maximum of 12 weeks
  • you are given ongoing support after the diet

Very low calorie diets are the most restrictive form of dieting, severely reducing calorie intake, so medical supervision is important.

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Alternatives To Calorie Restriction

Intermittent Fasting Vs Calorie Restriction: Which Approach Can Propel ...

Long-term adherence to CR is often difficult. Research has investigated alternative approaches that mimic the beneficial outcomes of CR. Calorie restriction mimetics include plant or pharmaceutical compounds that mimic the beneficial effects of CR by targeting metabolic aging processes. CR mimetics include resveratrol, and the pharmaceutical medications rapamycin and metformin.

Research has shown that individuals following an intermittent fasting regimen may experience similar health benefits compared to CR, such as weight loss and improvements in cardiometabolic risk factors. IF is a dietary approach that involves periodically abstaining from calorie-containing food and beverages on a recurring basis. Further, long-term studies of IF in humans demonstrated no serious adverse effects and similar adherence rates in IF and CR.

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Curcumin Green Tea And Ginkgo Biloba

Several compounds have been investigated as CRMs, with encouraging preliminary results in animal models. Tetrahydrocurcumin and green tea polyphenols have both demonstrated increases in average and maximum lifespans in mice.114 The effects were observed when the mice received treatments by month 13 , and in the case of green tea extract, the treatment had no effect on body weight. An investigation of ginkgo biloba on cognitive behavior in male Fischer rats revealed an unexpected, statistically significant increase in average lifespan when compared to controls .115 The NIA Aging Intervention Testing program,116,117 a multi-center study on longevity-enhancing compounds, has already identified life-extending or CR mimetic activities in rapamycin118,119 and aspirin120 in rodents, and is currently testing other potential compounds including medium chain triglycerides, caffeic acid esters, and curcumin.121

Caloric Restriction In Humans Mitigates Disease Risk

There is a growing body of evidence suggesting that CR may reduce disease risk factors, which may have a direct influence on healthspan . Several observational studies have tracked the effects of CR on lean, healthy individuals, and have demonstrated that moderate CR improves heart function, reduces markers of inflammation , reduces risk factors for cardiovascular disease and reduces diabetes risk factors .22-25 CR in healthy individuals has also been associated with reductions in circulating insulin-like growth factor-1 , and cyclooxygenase II ,26 all of which may be indicative of a decreased risk of certain cancers. Epidemiological data shows an association between higher plasma IGF-1 concentrations and a greater risk of breast,27 prostate,28 and colon cancers.29 COX-2, in addition to its role in inflammation, can promote the growth and spread of tumors.30-32

Similar results have been observed from the CALERIE studies at Washington University on a separate group of 5060-year-old non-obese overweight volunteers after one year of either CR or exercise training of equivalent energy expenditure .45 CR improved cardiovascular parameters ,46 lowered C-reactive protein and insulin resistance,47 and lowered circulating thyroid hormone T348 and fasting plasma insulin.49

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Disclaimer And Safety Information

This information is not intended to replace the attention or advice of a physician or other qualified health care professional. Anyone who wishes to embark on any dietary, drug, exercise, or other lifestyle change intended to prevent or treat a specific disease or condition should first consult with and seek clearance from a physician or other qualified health care professional. Pregnant women in particular should seek the advice of a physician before using any protocol listed on this website. The protocols described on this website are for adults only, unless otherwise specified. Product labels may contain important safety information and the most recent product information provided by the product manufacturers should be carefully reviewed prior to use to verify the dose, administration, and contraindications. National, state, and local laws may vary regarding the use and application of many of the therapies discussed. The reader assumes the risk of any injuries. The authors and publishers, their affiliates and assigns are not liable for any injury and/or damage to persons arising from this protocol and expressly disclaim responsibility for any adverse effects resulting from the use of the information contained herein.

Extended Data Fig 1 Additional Measures Of Glucose Homeostasis In Male C57bl/6j Mice

How to Follow the Calorie Restriction Diet

Food Consumption Glucose and insulin tolerance tests after 13 or 14 weeks on the indicated diets. * symbol represents a significant difference versus AL-fed mice # symbol represents a significant difference versus Diluted AL-fed mice * symbol represents a significant difference versus MF.cr-fed mice based on Tukeys test post one-way ANOVA. Fasting blood glucose , fasting and glucose-stimulated insulin secretion , and calculated HOMA-IR . AL, n=9 Diluted AL, n=8 MF.cr, n=9 CR, n=9 biologically independent mice * symbol represents a significant difference versus AL-fed mice insulin levels in fasted and glucose-stimulated states were analyzed separately. All data are represented as mean±SEM.

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Calorie Restriction Diet Benefits And Risks

Calorie restriction is a type of diet that has been researched for over 70 years but still much remains to be known about its actions and effects on the functioning of the human body. So far scientists, have found out that it has promising effects on certain species of animals such as rodents, dogs, fish and even fungi. It has been shown that inducing calorie restriction in these animals slows down the aging process, vastly improving the lifespan beyond the average.

As of right now, studies are currently being done on primates to show if calorie restriction actually works on them. And even though they are producing good results, it is still uncertain if this diet regimen will provide long-term benefits on primates, which include us, humans.

How Many Calories Is Too Few

Without adequate nutrition, extreme calorie restriction in which calorie intake is restricted by approximately 40% can be harmful. In a human study published in 1950, participants reduced energy intake by 40% with a low intake of protein, fruits, and vegetables in order to mimic dietary conditions during World War II. Side effects of this intervention included reduced aerobic capacity, weakness, severe painful edema in the legs, and psychological effects, such as depression, suicidal thoughts, confusion, apathy, and loss of sex drive. Its important to note that the extreme diet design in the study differed from CR diets in which individuals consume recommended nutrient intakes.

In elderly adults, long-term CR may be associated with a reduction in lean muscle mass and bone density, specifically at the site of osteoporotic fractures. Results in animal studies and CRON participants demonstrate that, while bone density is reduced, there is less turnover of bone, which can improve the quality and strength of bones. Interestingly, exercise may mediate some of the adverse effects in older adults. In a one-year, randomized controlled trial of obese adults over 65 years old, bone mineral density and lean body mass decreased less when a CR diet was combined with exercise than it did in the diet group alone. Physical function, including balance and strength, was also improved in the diet-exercise group.

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Extended Data Fig 6 The Effect Of Three Calorie Restriction Regimens On Female C57bl/6j Mice

Outline of feeding regimens: AL, Diluted AL, CR and MF.cr. Body composition measurement over 16 weeks on diet total body weight , lean mass , fat mass and adiposity . Glucose and insulin tolerance tests after 9 or 10 weeks on the indicated diets. * symbol represents a significant difference versus AL-fed mice # symbol represents a significant difference versus Diluted AL-fed mice @ symbol represents a significant difference versus MF.cr-fed mice based on Tukeys test post one-way ANOVA. Metabolic chamber analysis of mice fed the indicated diets. Respiratory exchange ratio vs. time Fuel utilization was calculated for the 24-hour period following the indicated refeeding time . * symbol represents a significant difference versus AL # symbol represents a significant difference versus Diluted AL based on Tukeys test post one-way ANOVA performed separately for FAO and C/PO). Energy expenditure as a function of lean mass was calculated for the 24-hour period following the indicated refeeding time . k) Food consumption . All data are represented as mean±SEM.

How Many Calories Should I Eat On A Calorie Restricted Diet

How effective is calorie restriction

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In respect to this, does calorie restriction work for weight loss?

No, they’re not. Calorie restriction means reducing average daily caloric intake below what is typical or habitual, without malnutrition or deprivation of essential nutrients.

Subsequently, question is, how many calories can I have while fasting? On the fasting days, it’s recommended that women eat 500 calories and men eat 600 calories. For example, you might eat normally every day of the week except Mondays and Thursdays. For those two days, you eat two small meals .

Also, what can you eat on a calorie restricted diet?

Here are a few examples of foods that may be suitable for fast days:

  • A generous portion of vegetables.
  • Natural yogurt with berries.
  • Grilled fish or lean meat.
  • Cauliflower rice.
  • Soups
  • Low-calorie cup soups.
  • Black coffee.
  • How many calories should I eat in a day to lose weight?

    The average woman needs to eat about 2,000 calories per day to maintain her weight, and 1,500 calories per day to lose one pound of weight per week. Meanwhile, the average man needs 2,500 calories to maintain, and 2,000 to lose one pound of weight per week. However, this depends on numerous factors.

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    Trying To Lose Weight You May Have Come Across Various Diet Plans That Either Focus On Time

    Written by Longjam Dineshwori | Updated : May 26, 2022 1:31 PM IST

    People wishing to lose weight may be looking for the best diet trends to follow. If you’re one of them, you may be wondering if you should opt for calorie restriction diet or time-restricted eating. You have come to the right place!

    In an exclusive interaction with TheHealthSite, Dr. Varsha Gorey, Senior Clinical Dietitian at Apollo hospitals, Navi Mumbai, explains the differences between calorie-restricted diet and time-restricted eating, as well as the efficacy and safety of popular weight loss diet trends. Excerpts:

    Focusing On Protein And Fiber

    Hunger can be difficult for people who do not have experience of fasting for several hours each day. Choosing foods rich in fiber and protein during the eating window can help to combat this. These nutrients help a person feel full and can prevent a blood sugar crash or food cravings.

    For example, eat whole-grain bread and pasta rather than white or refined grains. Choose a snack which includes protein in the form of lean meat, egg, tofu, or nuts.

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    Example Of What I Ate Today On Cr



    Baby Spinach

    Adding some fat to the smoothie is good to help absorb the nutrients. Try adding walnuts, avocado, or whatever you prefer. Green smoothies are great for times when youre in a rush. In the summer Ill usually have a smoothie every day. Ill make it and pop it in the freezer for a bit until its nice and cold and then drink slowly.

    Tip: Adding blueberries to the green smoothie will slow the absorption of sugar which will help prevent a sudden rise in blood sugar. This is great for those of you who are at risk of blood sugar problems or if you already have type 2 diabetes.



    Chillie flakes

    A pretty simple and filling meal. Its not something that I eat every day, but calorie restriction doesnt have to be complicated either.

    Remember, its not all about what you eat, its also about what you dont eat

    For more information on how to go on a calorie restriction diet or learn more about the diet, I highly recommend checking out the books Ive listed below.

    The CR Way was written by Paul McGlothin & Meredith Averill. Paul and Meredith have been featured on many of the major TV networks, sharing their experience of practicing long-term calorie restriction.

    They have continued to pursue the understanding and implementation of calorie restriction in humans and have contributed greatly over the years in helping us understand how calorie restriction benefits human health.

    Cr Modulates Dna Methylation

    The CRONA Study: How Calorie Restriction Affects Aging and Health

    CR increased the methylation level of proto-oncogene RAS in a rat model when compared to ad libitum fed animals . A hypermethylated gene promoter is often recognized by transcriptional repressor complexes that silence the expression of these oncogenes, which contributes to the cancer prevention of CR . In a human cell model of CR, the E2F-1 binding site in the promoter of the p16Ink4a gene was hypermethylated. This DNA hypermethylation blocked access of E2F-1 to the p16Ink4a promoter, resulting in p16Ink4a down-regulation, thus contributing to CR-induced life-span extension .

    The effects of CR persist after it has been discontinued. This cellular memory of CR was accompanied by DNA methylation changes in an animal model following 1 month of CR. Promoter hypomethylation and concomitant increased Nts1 expression in various tissues persisted after CR was discontinued and animals given free access to food .

    Obesity is an important metabolic disorder in humans that is closely associated with recognized causes of accelerated aging and increased mortality such as diabetes, hypertension or cancer . Therefore, the anti-aging effects of CR should have an impact on the progression of obesity and are used in clinical weight control interventions . The practice of CR by obese humans revealed that hypocaloric diets cause DNA methylation changes in specific loci ATP10A , WT1 and TNF-, which could be used as early indicators of a response to CR .

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    How To Start A Calorie Restriction Diet

    Disclosure: This article may contain affiliate links. If you decide to make a purchase, I may make a small commission at no extra cost to you.

      Starting a calorie restriction diet could possibly be the best thing you can do for your health and longevity, but its not the easiest thing the world for most people. Only those with a high level of discipline, determination, and belief that it works have been able to stick it out long term.

      People who practice a CR Diet do so in many different ways, there is no single definition of what a CR diet should comprise of when it comes to the foods we include or the macronutrient ratios we adhere to. How we practice calorie restriction can be guided by biomarkers and by how we feel.

      In this article, Ill go through the main things that you should be aware of if youre looking at using calorie restriction as a means to improve your health and lifespan. Id also recommend that you read more about the benefits of CR, this will give you some encouragement to stick with the diet long enough to reap the rewards.

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