Dangers of very low calories

jogman

I’m curious on everyone’s thoughts on very low calorie diets. I often hear the rhetoric that one shouldn’t go below 1200 calories because it is “dangerous”. If I put aside the valid arguments around eating disorders and proper nutrition (let’s assume one takes multi-vitamins to supplement), wouldn’t the energy balance equation take care of itself. Eating in an energy deficit would just mean my energy (calories out) would come from either the food I ingest or my body’s stores (glycogen or fat). If my body’s reserves ran out, I might enter the danger zone however, if I have a lot of fat, that could take some time. So is it just a perpetuated myth of some “dangerous” threshold one shouldn’t go below or is there something else to it? Thanks in advance for your thoughts.

AnnPT77

There are essential nutrients that are not in multi-vitamins (i.e., nutrients your body can't manufacture from others). As an old person, I've seen many essential or beneficial nutrients 'discovered by science' over my lifetime, after which they may be included in supplements like vitamins. They've been in foods all along, so I don't personally consider multi-vitamins a good bet except as insurance on top of good nutrition. (I've actually had personal conversation with nutritional researchers who feel pretty much the same way, that people are foolish to rely on supplements like those for core nutrition.)

Note that your calories-out can come not only from food, glycogen, or stored body fat, but also from lean tissue. Research suggests that we can metabolize a limited amount of body fat daily per pound of fat we have, though exact estimates of those limits differ. Certainly, some people lose weight rapidly enough to lose lean tissue, such as muscle.

If your calorie intake is too low, your body will slow down bodily processes it considers less vital to survival. The early ones are not so worrisome (fidgeting reduction for example), but it proceeds to some most people consider undesirable even if not life threatening (fatigue, weakness, slow hair growth (so breakage and thinning), brittle nails), to others of much greater concern. Immune system can be compromised, for one, a thing I wouldn't love to think about ever, let alone in a pandemic. Another would be rebuilding bone, which is a continuous process to maintain the body in good condition.

Certain health conditions become more likely with too-low calorie intake, such as gallbladder disease. Brain fog is common, among people who are getting too few calories.

As an extreme case, this is sobering, for example:

https://community.myfitnesspal.com/en/discussion/10761904/under-1200-for-weight-loss/p1

We don't really know what weaknesses our individual bodies may have, that will show up when we put them under unnecessarily much stress . . . and an extreme calorie deficit is a physical stress, no question.

Some of the above consequences don't show up until it's too late to do anything to prevent them, and some can have permanent impacts.

None of these bad consequences are *certain* to occur with too-rapid weight loss. It's a question of how much risk you like in your life.

Personally, I'm of the opinion that we can train our bodies, to some extent, to deal with what we require of them. I'd rather train my body to thrive as much as possible alongside a healthfully moderate weight loss (if needed), rather than training it to limp along on minimal calories. Some of the consequences of low calorie intake, over a long-ish period, can result in a lowered calorie requirement for maintenance, making it harder to stay at a healthy weight, or to lose weight next time if there's regain (as there is in the overwhelming majority of cases).

Just a few thoughts.

ninerbuff

Your body is VERY SMART. It knows what it needs to do for survival. So if your calorie deficit is too large or extreme, you risk not only NOT getting in essential nutrients for the body, but the body reacts to this stimuli by slowing metabolic rate and not ONLY using fat for energy but muscle as well. And the more muscle you lose, the weaker you become in that muscle and that can affect how you move it as well as the support for the joints it's connected to.
Think of a lean older person who doesn't exercise. How frail are they and susceptible to broken bones and weakness?
Can doing extreme calorie deficit be dangerous? Well it does depend on your body fat percentage to an extent. Someone who only has normal to low body fat already and decides they are still to fat and do extreme calorie deficit will be at much higher risk than someone who is say carries 40% of body fat.
And while what you stated above sound theoretically correct, you still have to take into consideration that YOU DON'T have control of how your body reacts to it. Your hair might start falling out. You may suffer from severe fatigue.
It's always best IMO to do everything safely and try to find a deficit that works for weight loss but doesn't cause any issues.

A.C.E. Certified Personal and Group Fitness Trainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 30 years and have studied kinesiology and nutrition

Wendyanneroberts

Above are 2 detailed explanations why it is a bad idea. My personal experience; I was on a diet, which was tracked through my health authority (at the beginning). I stopped attending meetings but continued with diet. Thinking it was safe, as NHS. (As a very sedentary, as disabled, late 40's female). Was very obese and struggling to lose weight, on my own). Didn't track calories at the time, but weighed all food and kept accurate logs. Over a few weeks, I became very unwell. Looking back, with experience gained, it was linked to inadequate nutrition, diet at that time averaged between 800 and
1,000 calories a day.

1) My heart condition was consistently worse, as my body was under stress.

2) Developed (and still have for life) an autoimmune disease. Two of my main problems, that I manage are extreme exhaustion and severe sight problems. Affecting daily life, at times I can barely see and can't go out alone.

3) Brain fog (also linked to autoimmune condition), but vastly improved and managed with balance nutrition. Especially by getting enough Fat, my cardiologist had recommended a low fat diet. But without targets, I had cut fat almost completely. At times, unable to hold conversation or drive.

4) Hair loss, remaining very thin hair, like straw, breaking away.

5) Brittle nails, that stopped growing and fell out. Bare nail beds, so sore and bled.

6) Weakened muscles, meant physically disabled condition, deteriorated.

These are the main symptoms, some are irreversible. Lived with and managed, rather than cured. Was a long road to recovery, 7 years later, still affect daily living. Was physically disabled and needed help before, but add my sight condition, I can not go out alone. No longer drive or see to cross the road.

Perhaps I would have developed the auto immune condition anyway. Who knows??? But putting my body under severe stress, certainly contributed. At the time, my BMI was still very obese. Using your theory I had fat to "support me", I didn't

Why take the risk!

A long post, but if this helps anyone else avoid my experience, then I'm glad.

(Incidentally, my daily activities, even for me plummeted. Barely able to dress, with help. Laying on sofa, barely able to sit, let alone move. I didn't exercise in the conventional way, but my neat dropped too. I stopped losing weight.

Since then, finding and using MFP, as intended. Averaging 1,600 calories a day, I'm maintaining a 66lb weight loss. So more food, improved my health and enabled me to lose in a healthy manner).

Cherimoose

jogman wrote: »

So is it just a perpetuated myth of some “dangerous” threshold one shouldn’t go below or is there something else to it?

The 1200 threshold is kind of arbitrary, like the "drink 8 glasses of water" advice and "walk 10,000 steps". It depends on your size & activity level - a sedentary, small female might do fine under 1200 for a while, but 1500 could be too low for a highly active male. I'd say your calorie deficit is a more important threshold. Over about a 1500 deficit (3 lbs/week) increases the risk of gall stones, which can be life-threatening, so it should be medically supervised.. especially if you have other medical conditions.

wunderkindking

The things I have not seen mentioned here are:

Too fast on the fat loss and you risk gallbladder issues.
https://www.hopkinsmedicine.org/health/conditions-and-diseases/gallstones#:~:text=As the body metabolizes fat,to become overconcentrated with cholesterol.

From there: Rapid weight loss. As the body metabolizes fat during rapid weight loss, it causes the liver to secrete extra cholesterol into bile, which can cause gallstones.


Also: You need fat to absorb some vitamins. Fat in particular.

Fflpnari

I did 800 calories a day. Lost 126 pounds in 8 months. Started eating somewhat normal when I hit my goal. I gained weight back so fast!! It totally messed my hunger ques. I felt like sheeeeet all the time. I had my gallbladder removed. I started getting dizzy. I have a really low heart rate with AV block probably from the VLCD. Make lifetime habits that will stick it is actually much easier than you think.

I regained most of that weight. I got my head in a better place and lost 100lbs again. Now am maintaining. EAting healthy, 2400 calories a day. Staying active.

RunsWithBees

If you treat your body in this horrible way you risk also suffering negative mental repercussions in addition to the possibly permanent or fatal physical side effects. It’s been studied, look up The Minnesota Starvation Experiment. The volunteers that were able to complete the experiment developed an obsession with food that lasted long after the experiment ended. An excerpt from a book about the study:
“To everyone's relief, the subjects' moods and social behavior stabilized three months later. But when it came to eating, the men agreed they were not "back to normal." Many ate "more or less continuously" and a subgroup of the subjects continued bingeing to the point of sickness, even eight months later. At least one man was hospitalized for several days after having his stomach pumped. "Hunger differs radically from the delightful nuances of appetite," wrote the researchers in ‘Men and Hunger’. Semi-starvation had temporarily changed these men in many ways, but what seemed to linger long after was this inability to distinguish between the constant gnawing of hunger and normal appetite.”

Speakeasy76

RunsWithBees wrote: »

If you treat your body in this horrible way you risk also suffering negative mental repercussions in addition to the possibly permanent or fatal physical side effects. It’s been studied, look up The Minnesota Starvation Experiment. The volunteers that were able to complete the experiment developed an obsession with food that lasted long after the experiment ended. An excerpt from a book about the study:
“To everyone's relief, the subjects' moods and social behavior stabilized three months later. But when it came to eating, the men agreed they were not "back to normal." Many ate "more or less continuously" and a subgroup of the subjects continued bingeing to the point of sickness, even eight months later. At least one man was hospitalized for several days after having his stomach pumped. "Hunger differs radically from the delightful nuances of appetite," wrote the researchers in ‘Men and Hunger’. Semi-starvation had temporarily changed these men in many ways, but what seemed to linger long after was this inability to distinguish between the constant gnawing of hunger and normal appetite.”

Wow, reading about this study validates what happened to me and what I experienced . I put myself on a 900-calorie a day diet as a mildly overweight 14-year old, which I them cut down to 500. However, it wasn't months that my eating wasn't back to my normal, but years and years. I already didn't have great hanger/satiety cues to begin with,but that extreme diet really messed it up. Not only that,but often just the idea of limiting the amount that I ate in order to lose weight brought that fear of starving (them bingeing) back....even if I never dieted that extremely again.

Like I said, it took me years (like 20) to feel better about myself when it came to eating more normally...and I say "more," because there's still a part of me that has to be really diligent about secret bingeing. That's why I cringe at hearing other people embarking on more extreme diets.

7rainbow

There are a million reasons I could go into but one big one for me was sleep. I fell asleep everyday in the middle of the day. I couldn't control it. It went on for years just falling asleep in class which was bad but it was manageable. The worst was at work however. I literally fell asleep in one on one convos in my boss. I got about 7-7.5 hours of sleep a night so I knew it wasn't that, and I was sure it wasn't narcolepsy. Once I started eating normal I soon noticed the problem went away.

janejellyroll

7rainbow wrote: »

There are a million reasons I could go into but one big one for me was sleep. I fell asleep everyday in the middle of the day. I couldn't control it. It went on for years just falling asleep in class which was bad but it was manageable. The worst was at work however. I literally fell asleep in one on one convos in my boss. I got about 7-7.5 hours of sleep a night so I knew it wasn't that, and I was sure it wasn't narcolepsy. Once I started eating normal I soon noticed the problem went away.

I had the opposite problem when I accidentally went too low (I was underestimating my activity level and exercise calories). I had trouble falling asleep and staying asleep, even when I felt exhausted. Like you, once I began eating more it resolved.

jogman

Thanks everyone for the response and input. I just needed some reassurance. I am 54 and spent the last three years losing weight from 295 to my current 207. I guess I will just stay the course to finish off the last 30 over the next 18 months.