Exactly What Is A Low Calorie Diet?

i think when your body can't function anymore, is when calories become too low... some people don't realize that the more you restrict yourself, the harder it will be to lose weight - if that is their goal... your metabolism needs fuel in order to work and that's as simple as you can get... i think going under 1200 (for women) is too low, esp. if you're also exercising, and feel 1500-1800 is acceptable... that's what i do anyway and it seems to be working... :o)

I'm losing weight on at least 3000 calories a day. I'm carrying quite a lot of lean mass for my height though. If you're sedentary and maintain weight on X calories of processed food, then in my opinion, eating below X calories is too low. Instead, increase food quality and start doing cardio and strength training. This will create the deficit. If you insist on restricting calories, never do so for more than 2 or 3 days in a row, and never go below 20% of your maintenance.

Oh, and if any diet was "the diet to end all diets", it would be BFFM.

I think this just proves that people are becoming less active. I believe the 2500 calories is based on having an active lifestyle. We're sitting on our butts! Hence the 1200 calorie guaranteed weightloss diets. You could lose weight in a coma with that one.

When I was in treatment, I was asked by my nutritionist how many calories a person needs if they are not moving at all and are in a coma. I thought the answer would be about 800. I was shocked to learn that the real answer is 1200-1400. If you're in a coma. If you're moving around at all, even if you're sitting on your butt, you need more.
I don't think I can really say "A man needs X calories and a woman needs Y calories". It varies so much from person to person, I don't think there is really any standard formula one can use.

The basis of the CR fad is animal studies showing that rats and mice fed very low calorie diets can as much as double their lifespans. Usually rodents are constantly breeding - but if they're starving they stop reproducing. Surprise! Constant breeding really takes it out of you. These poor animals also spend all their time huddled in their cages conserving energy. What a rotten life. I wouldn't wish that on any human.

At what point are calories "too low"?

If we are not talking about weight-loss, the calories are too low when your intake is below your resting metabolic rate. In other words, if you do not want to lose weight, but you eat less calories than you need to maintain your current weight – that is too low.

I'm no expert, but I think that 16-1800 calories is fine, whether you're actively trying to lose weight or not. Lately, I've been doing about ten minutes of exercise each day and usually stick to about 1300 calories, give or take a few. If I eat more than that, I get really overactive and less makes me feel tired. By the time I'm an adult (I'm 16) that 1300 that works perfectly for me will probably be a little higher. That 'magic number' is different for everyone, though. One of my friends (17) weighs 98lbs and eats at least 2000-2500 calories a day. No anorexia, no dieting, no exercise. Just a high metabolism.

"I personally feel that resistance and strength training play a significant role in preventing muscle wastage and metabolic sluggishness during lower calories. I also believe that calorie needs are linked to body composition rather than body weight. Those with more muscle mass need more energy to maintain that tissue."

This has been my experience. When I was obese and never exercised, I would maintain on 1200 calories a day. Now that I "lift heavy" (and do a moderate amount of cardio) I maintain on 2200 calories a day - which is a lot of food for a 5'3", 50 year old woman. I monitor my body composition with calipers: when I don't eat enough calories, or don't eat enough protein, I lose muscle.

Ryan and RedPanda--I tend to agree with you both. Lean body mass plays a huge role in how many calories are enough. I eat around 2400 calories a day and I maintain just fine...I'm even a bit underfat for my frame size (which I'm trying to correct by upping to 2800 calories a day). I am very active though, so I'd guess that if I continued to eat this way and be very sedentary I'd probably gain.

That being said...the CR movement does have a valid point when it comes to nutrient maximization vs. calorie minimization. I try to do that so I can eat more of the foods I like. Spinach, for example, will provide more vitamins than say, white bread with a fraction of the calories. So if you eat a spinach salad instead of a PB and J on white, you'll save calories, feel about as satisfied, and get more nutrition so you'll feel better. I think processed foods in general are contributing to our eating too many calories with not enough nutrients. Therefore, our bodies always feel malnourished and are "starving" even when we've eaten.

I agree with Ryan, Jim, Red Panda, and Spectra. In my own very unscientific experience, source of calories matters more than calories. When I was eating not-so-clean (no sugar, no junk, but still eating a few diet foods), at 170lb with weight training and cardio, I needed to eat 1,400-1,500 to lose weight. As soon as I cleaned up my diet a bit, not anywhere close to bodybuilding perfection cause I'm a very undisciplined eater, but just quitting about 60% of the diet processed foods I used to eat, I started losing so fast I had to keep upping calories, and kept them at an average of 2,000 a day until I reached my goal weight, and then had to up to 2,500 for maintenance.

To me, the key question is why humans, with our big brains and big calculators and big computers, can't manage to keep our caloric intake and output in equilibrium. In other words, why are humans and our pets the only creatures on the planet who consistently overeat? We're not the only ones living with caloric abundance, but we've lost our "I'm full, so I should stop eating now" mechanism.

Four theories:

1. The processed foods - concentrated calories and artificial ingredients - confound our circuitry. Like putting an elephant on a 5-lb postal scale.

2. We're eating on the run, distractedly, so we're taking no pleasure in our foods. Maybe pleasure is the nutrient we have to get enough of in order to stop naturally. Ever eat a single M&M, slowly? Like really slowly? Try it, and you'll find you won't have a craving to eat a pound at a sitting.

3. Professor Wansink's book Mindless Eating suggests that clever marketing may induce us to eat more than we think we're eating. Huge plates, big bowls and spoons, Super-Sized portions, etc. are turning us into a nation of unintentional gluttons.

4. Michael Pollan (The Omnivore's Dilemma) and Marion Nestle (What to Eat) both look at our overconsumption with a naturalist's eye. The US food industry produces over 3900 calories per day per person - about double what's needed, on average. To grow and satisfy shareholders, these companies will do everything they can - are required by LAW to do everything they can - to get us to buy and then consume those extra calories.

I eat a whole-foods, plant-based diet, and I've found that calorie counting simply disappears as an issue when you keep out of your body foods that don't belong in your body. No dieting, no counting, no obsessing. Just improved health and a normal physique.

Is it calorically restricted? I don't have the slightest idea - I eat until I'm satisfied, and I don't worry about it. Like every other animal on the planet does.

"I eat a whole-foods, plant-based diet, and I've found that calorie counting simply disappears as an issue when you keep out of your body foods that don't belong in your body."

I'm finding the same thing works with a whole-foods, animal-based diet too.

Humans AREN'T the only animals with the problem of overconsumption. Domestic pets are getting fatter and fatter as well. Wild animals have to search for their food; domesticated ones are fed a diet of processed pet foods. Ideally, dogs should be fed a diet of raw meat and bones and hide...like in the wild. Just like humans should be eating mostly unprocessed vegetables, fruits, meats, and grains. UNPROCESSED is key!!

I'm a 1200 calorie a day diet...and I've lost about 45 kilos. I think it will be difficult bringing the amount up once I'm at my goal weight.

Things that worry me are putting on weight, yoyoing, keeping up the healthy eating...

Spectra, I agree, but one significant difference is that we tend to get to choose, whether consciously or not, what we're eating, whereas pets get what we give them, both in quality and amounts. (Some outdoor cats hunt, but they're usually fed kibble on top of that.)