Is a Fast Rate of Weight Loss Dangerous?

I managed to increase my calories to close to 2000 calories and fixed my macro percentages to where they should be at and am watching my sugar intake. The last few days I’ve been seeing a weight loss rate of 1 pound per day. I heard that it is not safe to lose more than 2 pounds per week. I know it’s only been a few days and the weight loss rate should drop eventually. Is there a point when fast rate weight loss does become dangerous? Or am I falling for nonsense?

It is probably just water, your weight should stabilize after 2 or 3 weeks.

Losing weight too quickly can be dangerous when we are talking about losing actual fat and muscle. Since you have adjusted your macros and are watching your sugar, it is probably due to cleaning up your diet. Water weight can be lost and regained relatively quickly. Carbohydrates encourage your body to retain water-- generally, the more carbs you eat, the more water you will retain and vice versa. The body converts carbs to glycogen, which is then stored in the muscles for energy. For about every gram of glycogen stored in the body, you gain approximately 2.7 grams of water.

In my opinion (be aware I am in no way qualified to give medical advice), some of the things that cause rapid fat loss are dangerous, but if your diets in order, make the most of it.

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I’m with dagill2 here. Many diet systems like Lyle McDonald’s Rapid Fat Loss method actually aim for very rapid fat loss. Losing weight ‘too fast’ becomes a problem if you only eat like 600 calories a day like many fad diets have you eat or if your macros are so screwed you are also losing muscle.

To add to what others have said, don’t get too hung up on what the scale’s doing right after you make some kind of change. I can swing 6 or 7 pounds over the course of one weekend if I eat a lot of salty foods and load up on carbs. Then I’ll have a 1-2 pound weight loss every day when I dial things back in on Monday. That’s mostly water and glycogen, and it will not be sustained for long. That’s fine and normal.

You seem to be eating a sensible amount of food. Once you keep things up for an extended period, patterns will emerge. If you’re like me and cheat on weekends occasionally, your weight might jump up a lot. But that doesn’t mean I’m gaining 6 pounds of fat in 2 days. The pattern I pay attention to is my end-of-workweek weigh-in. I want to be coming in a pound or two lighter each Friday, regardless of the wacky things the scale may do during that particular week.

Don’t get upset when the scale starts moving slower. Stick to your plan over time and look for patterns, which should include lower overall scale weight from one week to the next.

Ok I won’t be worried about it. I’m ecstatic that I’m losing weight again, but it came with some lose skin.

Everything depends on context.

Since you managed to increase your calories and are still seeing weight loss, it is probably a combination of what others have mentioned here-shedding water weight and possibly glycogen–and that your metabolism has finally speeded up because you’re actually fueling it now.

Rules of thumb: If you are feeling good, not really hungry (I’m not talking about cravings for bad foods, I’m talking physical hunger), then faster fat loss is possible and not dangerous if you are starting from a more overweight spot.

If you are dragging energy wise, or can’t sleep, or always sleepy, then fast weight loss is usually a bad thing because you’re not actually feeding your body enough to run its systems and it is trying to tell you that.

If you are feeling ok but ragingly hungry all the time then fast weight loss is bad because you are not feeding your body enough and it is going to start to ratchet down the metabolism’s speed to try to compensate. For some reason people chop calories off at the knees instead of chipping away…chopping them off at the knees is bad practice because there is only so low you can go before you can’t drop any more. There IS a calorie ‘floor’…at least if you have any interest in being healthy and not damaging yourself. That’s why small changes are most effective–get the most progress out of the least change. Once you reach the floor you have nowhere to go and will have to stop the diet and reverse back in calories slowly to rehabilitate your metabolism.

This is the reason “eat less”–while very true–is too general advice. Alternatively if you kept your calories where they were and simply added activity, you would still create a deficit and lose weight, but feel better. Generally speaking it is better to move MORE than to eat LESS (refer again to the calorie floor concept). This is general advice, not for you specifically. Being that you increased your calories and are seeing progress I am not suggesting you change what you are doing. Wait til it stops working, THEN change something.

In other words, once you stop losing weight entirely for 2 weeks, then add activity OR chisel some calories out. Not both at the same time. Try one, wait a week, add the other on top. Get the most out of the least. This takes longer but means less suffering and less change of metabolic damage.

For you, you’re fine right now. The key danger to losing weight super fast comes mostly when either 1) your calories are already significantly low or 2) you are already pretty lean. It is harder to lose fat quickly when you are very lean, this is why physique and figure competitors diet slowly. The leaner you are, the touchier things get–this is why they track everything they do. Obviously, if you are close to the calorie floor its dangerous to lose weight quickly.

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