I Need How Many Calories?!!

2000 calories a day is not what any average adult needs to maintain her health, weight and wellbeing. That’s an inadequate daily energy intake. That’s right. It’s too low. And if you are younger than 25, then it’s far too low.

Alright, let's get into this…

Ju Piesco Flickr.com

Ju Piesco Flickr.com

Introduction and Some Nomenclature 

This blog post entry used to be called “Do I need 2500 calories?” and it tends to be where many begin their investigations on this site because it has been so heavily linked to by other sites. However, the definitive paper on this topic is now: Homeodynamic Recovery Method, Doubly-Labeled Water Method Trials and Temperament-Based Treatment.

Eating Disorders

Many of you visiting here for the first time may not have ever come across the term eating disorder spectrum, and it does not refer to anorexia alone. It includes: restriction/reactive eating cycles, bulimia, orthorexia and anorexia athletica as well as anorexia nervosa.

While the Diagnostic and Statistical Manual For Mental Illness (DSM-IV), now DSM-5 identifies all these conditions as distinct, they are neurobiologically all one condition. That is why patients will often express multiple facets of the condition at once, or shift from one facet to another over time as well.

The eating disorder spectrum is a broad spectrum and just under a third of our population resides somewhere on that spectrum. It is a lifelong chronic neurobiological condition and it has two states: active and remission.

You cannot be ‘cured’ from this condition once it is activated,
but you can enter a robust and often permanent remission.

For those who might be a bit taken aback by the idea that a third of our population has this condition, I reference the entire spectrum condition. 1

These are genetically determined conditions, however the condition can lie dormant. The most common trigger for activating the condition is dieting, or restriction of calorie intake. However, illness, trauma and other significant stressors can activate the condition as well.

The mean age of onset is approximately 11 years old 2, however “picky-eating” and/or gastrointestinal illness in early childhood is highly correlated with later onset of eating disorders as well. 3

The Facets of Restrictive Eating: It’s About the Food.

Everyone assumes that this condition is only about anorexia nervosa and most people have several misunderstandings about what anorexia nervosa is as well.

As best as we can define this condition at present,
food becomes misidentified as a threat.

The amygdala, one of the emotional centers in the brain associated with threat identification and the fear response, appears to have abnormalities in function for those with this condition (along with other associated brain structures), as per the published research of Walter Kaye, Janice Russell and their respective colleagues.

A blog post of relevance to the genetic component is: The Genetic Superpowers: Another Way to Frame Eating Disorders?

Our preferred response to any threat is avoidance.

Of course that is a useful survival response when the threat is valid, such as a predator moving around in the bushes nearby.

However, when food becomes threatening, then the person affected is now dealing with two monstrous problems:

  1. the sensation that food is a threat is nonsensical to the conscious mind and,
  2. it is impossible to completely avoid food intake because we have to eat to live.

Because being afraid of food is confusing to our conscious minds, the person with this condition scans the environment to try to explain to herself, or himself, why food has become a threat. In today’s world, the most common explanation is that the food will make them fat or unhealthy.  A few hundred years ago, the more common explanation was that food was only restorative for the putrid physical body and that spirituality and attaining a state of transcendence and closeness to God required the avoidance of food.

Just because the conscious mind has to explain the fear of food within a contemporary and changeable framework does not mean that the condition is made-up or caused by societal influence. Without the genetic predisposition, a person does not become anorexic simply because our society is disproportionately focused on unhealthy levels of thinness.

However, the fact that our society discriminates against fat and reveres thinness does mean that many more individuals with the genetic predisposition are liable to develop an eating disorder, because they are going to restrict food intake to try to achieve acceptable levels of thinness and then find that food becomes typecast as an enemy in their own minds.

Most with an active eating disorder do not necessarily connect the physiological responses they experience around food with some of the compulsions and behaviors that develop from that discomfort.

When the amygdala receives information from our senses that there is a possible threat nearby, then it generates a cascade of physiological responses that can be summed up as just unpleasant. These reactions drive us to want to remove ourselves from the stimulus that has been identified as a threat.

So What About the Food?

What happens when you have to keep removing yourself from eating?

Your drive to avoid the food runs into the stronger drive to stay alive.

And here is where all the facets of the condition can be readily explained:

Anorexia Nervosa

Anorexia nervosa, the restriction of food intake is clearly the most well known of responses found in this spectrum disorder. The patient still eats and is extremely hungry, but creates as many distractions and compulsions as possible to minimize the food she must take in. Keep in mind that eating creates a massive fear response for everyone on this spectrum. And when I say she “creates” these distractions, it is not a choice, but rather a compulsion driven by the extreme physical and emotional discomfort that eating generates for her.

Restriction/Reactive Eating Cycles

Restriction/reactive eating cycles involve the patient having to wait until the hunger physically overtakes her. She may even develop elaborate rituals around when and how she may be able to succumb to the hunger as a way to try to alleviate the fear response she must endure while eating. These cycles will often progress to bulimia nervosa, where the patient has to alleviate the fear response post-reactive eating with compensatory restrictive behaviors (abuse of diuretics, laxatives and purging). 

Blog posts addressing restriction/reactive eating cycles in more detail include:

Binge Eating Disorder and Night Eating Syndrome

Binges Are Not Binges

Again, few patients experience only one facet in the progression of this condition and many slide in and out of these facets or express multiple facets at once.

Orthorexia Nervosa

Orthorexia nervosa is the application of fear-modulating behaviors that mimic obsessive-compulsivity. By eating only foods that are considered ‘clean’ or healthy, the patient tries to alleviate the fear of food by convincing herself that the food is not a threat to her as long as it is the right food, in the right amounts and eaten at the right times. A blog post addressing orthorexia nervosa in more detail can be found here: Orthoresxia I: Women Laughing Alone with Salad and Orthorexia II: Doubt & Certainty.

Anorexia Athletica

Anorexia athletica is also a common fear-modulating set of behaviors where the consumption of food can be deemed to be less of a threat if all the energy that was consumed is “burned off” in exercise. This blog post addresses anorexia athletica in more detail: Exercise as a way to restrict? You bet as well as Exercise II: Insidious Activity and Exercise III: Athletes the Picture of Health.

Functional hypothalamic amenorrhea is a synonym for what is often called the Female Athlete Triad: inadequate and improperly timed energy intake combined with amenorrhea or oligomenorrhea (absent or infrequent menstruation) and reduced bone mineral density. It is the result of anorexia athletica. Therefore the same recovery guidelines apply for the presence of the functional hypothalamic amenorrhea or female athlete triad as apply to any other facet of the same eating disorder spectrum.

A blog post pertaining to the issues surrounding this spectrum disorder and family planning can be found here: Reproductive Health I: Fertility and Pregnancy and Reproductive Health II: Kids or Not, It's Still Important.

The Phases of Recovery from an Eating Disorder post has the Telltale Dozen signs that you can review to determine whether you are likely to be on this spectrum or not. But chances are that if you have gotten this far in your reading, then you are pretty sure that you need to turn some things around when it comes to food, exercise and your health.

Many of you are probably already veterans, having gone through several rounds of attempting recovery either on your own, or cycling through various inpatient and outpatient services as well.

And the reason many of you end up at this particular blog entry, usually from other sites, is likely because someone has mentioned you need a lot of energy to restore your weight, your health and to enter a robust remission from an eating disorder (no matter what facet(s) dominate(s) your existence at the moment).

Important Medical Disclaimer

It is important to have any recovery effort from restrictive eating behaviors
overseen by medical professionals.

If you have been restricting to 1000 or less calories a day, or you have abused diuretics, laxatives or purged, then you need to increase up to the recovery guideline calorie amounts for your age/height/sex slowly. That usually requires increments of 200-250 calories every 2 to 3 days until you get to 2000 every day. At that point, you can jump to the final amount (2500-3500 depending on age, sex and height). Please keep in mind that slow increases in food intake do not lower the risk of refeeding syndrome.

Because electrolyte balances may be out of whack in starvation, moving the intake back up to normal levels does have medical risks associated with it. Re-feeding syndrome is a life-threatening, but completely treatable condition during this initial phase of recovery, as long as you receive immediate medical intervention.

If at anytime during the early phase of recovery you are dizzy, light-headed, feverish, vomit, experience severe swelling of the hands or feet, and/or experience chills and sweats, you need to seek immediate emergency care.

And remember, while the guidelines to achieve remission from an eating disorder that are found on this site are research-based, they are not to be construed as medical advice, nor do they replace in any way the necessity of medical oversight and input if you are attempting recovery from an eating disorder.

2500-3500 Calories A Day. Yes Really. 

It is by far one of the most common questions asked of me: “Do I need that many calories to recover?” The quick answer is always: “Yes.” However it's actually "No" because this range only applies to individuals who have not ever restricted their food intake or created energy deficits in their bodies. For someone pursing recovery from an eating disorder, this range is actually an absolute bare minimum that will only halt progressive depletion of energy.

The reason I get asked this so much is because it is understandable to assume that somehow how long you starve and how underweight you might become are going to change the terms of recovery and that perhaps creating energy deficits through excessive exercise or cycles of restriction (with periods of so-called bingeing) may be more benign and will require less energy intake in recovery to rectify the damage. Not so.

The severity of starvation does impact recovery somewhat but only in so far as the time it may take to recover.

Probably most of you are aware that the clinical marker for active anorexia is body mass index (BMI) 17.5 or less. However this is misleading because while the so-called healthy BMI range is 18.5-25 that does not mean that a single individual is at a healthy weight throughout that entire range. We each have a specific optimal weight.

I usually explain it this way:

If I take two women of the same height and one is naturally meant to be BMI 30 and the other is naturally BMI 23, then this is what happens when they both restrict calories:

  • The woman at BMI 30 diets down to BMI 23. Technically she is still in the healthy weight range and she receives compliments on her dieting efforts.
  • The woman at BMI 23 diets down to BMI 17. People are very worried.

Which one has an active eating disorder? They both do.

And in fact the woman who is now BMI 23 is actually more severely depleted in mass than the woman who is BMI 17. Sadly only the latter will likely receive any kind of professional help to get to remission from her eating disorder.

Here are the guidelines for when 2500 calories applies as a MINIMUM daily intake for recovery:

You are a 25+ year old female between 5’0” and 5’8” (152.4 to 173 cm) and,

The regular menstrual cycle has stopped and/or,

You have other symptoms of starvation: feeling the cold, fatigued, foggy headed, hair loss, brittle nails, dull skin and/or,

Even if you were only underweight/dieted for a very short space of time (a few months), these guidelines apply.

Here are the guidelines for when 3000 calories applies as a MINIMUM daily intake for recovery:

You are an under 25 year old female between 5’0” and 5’8” (152.4 to 173 cm) or an over 25 year old male between 5’4” and 6’0” (162.5 and 183 cm) and,

The regular menstrual cycle has stopped and/or,

You have other symptoms of starvation: feeling the cold, fatigued, foggy headed, hair loss, brittle nails, dull skin and/or,

Even if you were only underweight/dieted for a very short space of time (a few months), these guidelines apply.

Here are the guidelines for when 3500 calories applies as a MINIMUM daily intake for recovery:

You are an under 25 year old male between 5’4” and 6’0” (162.5 and 183 cm) or female with young children or an equivalent and unavoidable level of activity.

The regular menstrual cycle has stopped and/or,

You have other symptoms of starvation: feeling the cold, fatigued, foggy headed, hair loss, brittle nails, dull skin and/or,

Even if you were only underweight/dieted for a very short space of time (a few months), these guidelines apply.


If you are taller than the guidelines listed above, then add 200 calories to the guidelines that match your age and sex. If you are shorter than the guidelines listed above, then you may eat 200 calories less than what is suggested for your age and sex, however these are all minimum guidelines and everyone is expected to eat well above them for a good portion of the recovery process in any case. Please see this this blog post for more details: Extreme Hunger: What is it? And yes, if you are above average mass, then you too will need above average intake of food to support your energy requirements fully as well.

Everyone in recovery should cease all exercise and workouts and any discretionary activities. The energy you take in is required for weight restoration and repairs.

What If I Am Already Weight Restored?

A lot of people who ask this question have regained their weight by consuming somewhere between 1800-2200 calories a day instead of the suggested minimums found on this site.

Many continue to feel extremely hungry, suffer persistent symptoms of energy deficits (cold, tired, brittle hair and nails, irregular or absent menstrual cycle etc.) and continue to have restriction a primary driver in their day-to-day lives.

The answer? That’s right, eat to the minimum guidelines (and where your hunger takes you) until the weight restoration stops (yes, it does that) and the symptoms of energy depletion disappear and menstrual cycles return (when applicable).

It is possible to gain weight on 1600-2200 calories a day when recovering from the eating disorder spectrum because the metabolic rate is so suppressed. For further details on this please review: Gaining Weight Despite Calorie Restriction.

The body approaches recovery in the following way:

  1. keep everything suppressed and take the energy to deal with the backlog of cellular repair (leading to bloating and water retention initially) and sock the rest away in fat stores (usually disproportionately around the mid-section to insulate vital organs);
  2. assuming there is enough energy still coming in, then address longer term repair issues (bone density etc.) and begin to notch up metabolic rates and bring biological functions back on-line;
  3. assuming adequate energy continues to come in on a daily basis, then fire up the regular neuroendocrine system back to normal and allow the metabolic rate to go back to normal as well.

It is very easy to get stuck in the first and second phases of recovery because the natural inclination is to assume that if you are back at BMI 20 then you are recovered and need to start restricting calories to avoid getting huge.

While that may be an understandable inclination generated from eating disorder anxieties, it is a false one.

Recovery is not the opposite process of dieting. With dieting you create a calorie deficit so that your body makes up the difference by using energy stores in fat, bone, muscles and major organs.  But with recovery, you have to provide not only enough energy to replenish fat tissue, but also even more energy is required to reverse pervasive physiological damage.

When you dependably eat the minimum calories every day (and much more than that because you can't just tread water), you won’t get stuck in a quasi-recovered state that usually leads to relapse or a shift from frank anorexia to restrict/reactive eating cycles, bulimia or anorexia athletica.

You can adjust to the minimum guidelines at any point in your recovery.

If you are already "weight restored" and yet your period has not returned, then up the calories. You will not keep gaining and gaining. You need more energy in to normalize the neuroendocrine system and metabolic rate.

Once you hit your body’s optimal weight set point, then the metabolism is normalized and that means that the extra energy you were taking in for weight gain and repair now goes to the usual day-to-day functions that were not happening at all from the moment you first restricted calories (whenever that was).

You gain on the minimum guideline calories+ (that plus sign means more than minimum intake) and then you maintain on pretty close to that same amount. Shocking, but true.

The Facts

I expect many of you have seen popular media stories about how we all eat a third more calories than we think we do and the story usually wraps up by suggesting that this is why we are all getting ‘obese’ (cue ominous sawing violins now).

We Lie About What We Eat

Yes, in fact health survey after health survey, adult women report eating on average just under 2000 calories a day and men around 2500 calories a day. 4

And yet, when we actually measure the intake in laboratory settings rather than relying on self-generated food journals or survey responses, then we eat about one quarter to one third more than the surveys would suggest we are eating.

The measurement of dietary intake by self-report has played a central role in nutritional science for decades... Recently, the doubly-labeled water method has been validated for the measurement of total energy expenditure in free-living subjects, and this method can serve as a reference for validating the accuracy of self-reported energy intake. Such comparisons have been made in nine recent studies, and considerable inaccuracy in self-reports of energy intake has been documented. Reported intakes tend to be lower than expenditure and thus are often underestimates of true habitual energy intake. Because the degree of underreporting increases with intake, it is speculated that individuals tend to report intakes that are closer to perceived norms than to actual intake.” (emphasis mine). 5
Social desirability and social approval distort energy intake estimates from structured questionnaires, in a manner that appears to vary by educational status.” 6

Both 7 day or 14 day self-reports trials are all over the map in the actual under-reporting that occurs and many researchers will classify trial subjects as failed-dieters, obese, average-weighted etc. etc., which likely removes validity from the trial data as an inherent bias stands that obese individuals are more prone to underreport food intake—a bias that does not stand up in clinical trial scrutiny. And that bias fails to address other valid influences such as social desirability and approval as being strong motivators for the underreporting of food intake, as highlighted by JR Hebert and colleagues in 2002.

The underreporting for both men and women can range from 2% to 58%. However, in the one and only trial where two groups of women were identified as either non-restrictors or restrictors of food intake and all were weight-stable, the non-restricting group ate on average 2400 kcal/day and the restricting group eat just shy of 2000 kcal/day. 7 Admittedly this is a small study, but I use it because it provides an unrestricting control group at least.

If we average the studies reviewed by JR Hebert and his colleagues, then people eat on average 25% more than they think they do (or report that they do). As most adult women say they eat just shy of 2000 kcal/day, then on average they actually eat 2500 kcal/day to maintain their health and weight.

But the fact that we eat much more than we say we do does not have any correlation to ‘obesity’. It only scientifically correlates to the fact that our actual intakes maintain a steady optimal weight set point.

The Under 25’s

I want to address the fact that the studies that identify what teens and young adults actually require from a total energy expenditure point of view and what they actually consume is of particular concern and sex-based differences are present.

In self-reports that form the basis of calorie guidelines around the world, girls between the ages of 12-25 report they eat 2000 calories a day. Boys in that same age range, report they eat 2800 calories a day on average (see surveys mentioned above).

Given that the developmental process in that age range is distinct yet equivalent for both sexes, how is it that in self-reports females suggest they consume exactly what adult females say they consume, where as males at least suggest they consume 300 calories more a day than what their adult counterparts are saying they consume?

Even more worrisome is that there appears to be no doubly-labeled water trials that specifically identify what weight stable non-restricting adolescent and young adult females actually consume. Therefore, you will find recommendations that teenaged girls eat 2000 calories a day simply because self-reports and surveys suggest that is what they eat.

The appalling truth is that over half of teenage girls do not eat enough for health, energy and strength. They do not eat enough to feel or look their best. But it is the lower 25 percent of girls — the hungry one-fourth — who are at most risk. . . .” 8

Due to this gap in data, we have to extrapolate using comparative data from developing and adult males to conclude that actual calorie intake discrepancies between self-reports/surveys and actual intake suggest that females under the age of 25 actually require somewhere between 2800 to 3100 calories per day to maintain health and weight.

That suggests that females under the age of 25 (who are non-restrictors) feel compelled to under report their actual intake by closer to 30% and that likely a very large proportion of females under the age of 25 are indeed restrictors and are consuming some 30% less than what would be required to maintain their health and development.

What Do We Actually Eat

As you can see, it’s tough to figure out these days who’s doing the eating and whether they represent unrestrained or average eaters or not.

Here are the facts that we can glean so far:

Adult women (age 25+) do not eat only 2000 calories a day. Adult men (age 25+) do not eat only 2500 calories a day.

All the guidelines for calorie intakes you see in the world are based on self-reports and national surveys.

The surveys have all been shown to be inaccurate when doubly-labeled water methods are applied in laboratory settings. In fact, surveys and self-reports appear to underestimate actual intake by between 25 to 30%.

However, it is important to keep in mind that one population sub-group never answer these surveys by underestimating their actual food intake:

"Many individuals with eating disorders vastly overestimate how much they have eaten and how many calories or fat grams they have ingested, as well as the magnitude of expected weight gain." 9

Guess What This Means for Recovery Guidelines?

For those in recovery, you are being asked to eat what actual non-restricting individuals eat in the real world, not what they say they eat.

You enter recovery by making sure you do not restrict intake, and it stays that way for the rest of your life. While you will experience a period of extreme hunger (Extreme Hunger: What Is It?) well beyond the minimum guidelines above, that is specifically because you have weight to restore and damage to repair. Your extreme hunger will not persist beyond your recovery effort. But not restricting intake is something you will do for the rest of your life.

For more research details and references on this topic of calorie requirements, please read this more recent blog post Homeodynamic Recovery Method, Doubly-Labeled Water Method Trials and Temperament Based Treatment.

1. Shisslak, Catherine M., Marjorie Crago, and Linda S. Estes. "The spectrum of eating disturbances." International Journal of Eating Disorders 18, no. 3 (1995): 209-219.

 2. Bryant-Waugh, R., J. Knibbs, A. Fosson, Z. Kaminski, and B. Lask. "Long term follow up of patients with early onset anorexia nervosa." Archives of Disease in Childhood 63, no. 1 (1988): 5-9.

3. Jacobi, Corinna, W. Stewart Agras, Susan Bryson, and Lawrence D. Hammer. "Behavioral validation, precursors, and concomitants of picky eating in childhood." Journal of the American Academy of Child & Adolescent Psychiatry 42, no. 1 (2003): 76-84.

4. Statistics Canada Canadian Community Healthy Survey 2004; NHANES 1999-2000; National Diet and Nutrition Survey UK 2009

5. Schoeller, Dale A. "The energy balance equation: looking back and looking forward are two very different views." Nutrition reviews 67, no. 5 (2009): 249-254.

6.  Hebert, James R., Cara B. Ebbeling, Charles E. Matthews, Thomas G. Hurley, M. A. Yunsheng, Susan Druker, and Lynn Clemow. "Systematic errors in middle-aged women's estimates of energy intake: comparing three self-report measures to total energy expenditure from doubly labeled water." Annals of epidemiology 12, no. 8 (2002): 577-586.

7. Tuschl, Reinhard J., Petra Platte, Reinhold G. Laessle, Willibald Stichler, and Karl-Martin Pirke. "Energy expenditure and everyday eating behavior in healthy young women." The American journal of clinical nutrition 52, no. 1 (1990): 81-86.

8. Berg, Francie M. Afraid to eat: Children and teens in weight crisis. Healthy Weight Journal, 1997.

9. Thompson, Ron A., and Roberta Trattner Sherman. Eating disorders in sport. Routledge, 2011.