Is it healthy/unhealthy to consume too few calories so long as you're not starving yourself?

Question

Several online calorie calculators tell me I should be consuming between 2100-2500 calories a day to lose weight (around 3000 to maintain my weight). For the past few weeks, I've been counting about 1100-1200 calories a day after I take into account what I've burned on the treadmill and with weight lifting. I am aware that the online calculators are not 100% reliable, but I feel comfortable saying that I am consuming well under the daily limit needed to lose weight at a rate of a pound or two per week.

I am wondering if consuming too few calories is actually counter-productive and if I should raise my daily intake. Most of my caloric intake has been through protein shakes and protein bars and I eat small amounts of low-calorie food throughout the day to take the edge off my hunger, especially about an hour before bed. I guess my mentality has been that, if I am not hungry, my body is at equilibrium with my metabolism and everything's working as it should.

Answer 1

If you suppress your calories enough you can enter a "starvation mode", although there are a couple of points I'd make:

From the research, it takes a long time to see long lasting impacts from seriously reduced calories (let's say 1/2 of your maintenance needs). The mid-century Minnesota study ran for about a year. The results from that study are rather unnerving:

There were extreme reactions to the psychological effects during the experiment including self-mutilation... Participants exhibited a preoccupation with food... Sexual interest was drastically reduced, and ... showed signs of social withdrawal and isolation. The participants reported a decline in concentration, comprehension and judgment capabilities...There were marked declines in physiological processes indicative of decreases in each subject’s basal metabolic rate (the energy required by the body in a state of rest), reflected in reduced body temperature, respiration and heart rate. Some of the subjects exhibited edema in their extremities, presumably due to decreased levels of plasma proteins given that the body's ability to construct key proteins like albumin is based on available energy sources.

It's important to note however that the above was a study that required participation and very few people would voluntarily endure such mental and physical pain for an entire year.

The more realistic problem to "crash dieting" is that you're really not learning and adjusting to a long term and healthy way of eating. Living in a binary world of either (a) excess or (b) extreme deficiency is hard on the mind and body.

The optimal method for fat loss is to concentrate on a more prolonged and sustainable approach. Being slightly more aggressive (before a beach vacation), or slightly less concerned (around the holiday dinners) is normal. Focus on strength training which increases your calorie consumption at rest, and keeping a watchful eye on calories, especially cheap/empty sources that sneak into your diet and end of putting you in excess.

Summarized, the biggest points I would concrete to anyone regarding body composition (ie:, how much fat vs lean muscle mass you have) is:

1. Be aware of your calories. Know how much you're ingesting on average. Know what you can eat more of (veggies, chicken, etc) and know what is the equivalent of caloric atomic weapon (alcohol, refined carbs, munchies, etc).

2. Focus on protein. You'll almost never have enough and nearly everyone is lacking in this area.

3. Strength train. As noted above, you'll get a ~8% caloric boost 24/7/365 just by doing effective strength training.

4. Don't sweat the details beyond that.

Answer 2

1200-1500 is what my personal trainers years back told me was the range of calorie intake for losing fat, but honestly just the bare number of calories can only tell you so much. The right amount you should be eating to lose weight is just enough to keep your mind attentive and your body functioning at a high energy level. Protein shakes and bars are good for meeting your protein requirements, but that is still less than half your diet, you do need to consume carbohydrates and some fats, as well as ensuring that you are receiving enough vitamins and minerals and that you are hydrated. Ensure that there is vegetation in your diet. As long as you've eaten properly to keep everything in your body in working order, having less than the recommended calorie intake isn't a problem.

Answer 3

Are you absolutely sure that loosing 'weight' is your real goal, or do you really get a better body composition? You can loose weight consuming to little calories, but you are likely to loose the wrong kind of weight depending on how much you under eat and how much of your diet is made up of carbs. It is unhealthy to loose the wrong type of weight. Keep monitoring your body composition. If you are loosing weight and seeing improvements in your body fat percentage, than stick with it. Even (and this is controversial) if you are 'not' loosing weight and seeing improvements in your body fat percentage I would also suggest to stick with it. If you are loosing weight and not seeing improvements in your body fat percentage you are doing something wrong and you should probably increase your calories and make sure you consume the right type of calories at the right time. Change one thing at a time and see what happens. For example first try to change some carbs for fat and see what happens (make sure you have sufficient carbs for your workout though).