I’m 61 years old, very active, 5’ 7" and as of a seven days ago I was 181 lbs. After 7 days of a Nutri-Systems regimen (their food supplemented by other low-cal/low-fat food) I am now 6-7 pounds lighter. This, verified by two scales.
So, what’s going on? While I’m pleased with losing 6-7 lbs, that just doesn’t seem logical, even with the exercise I get (1 hour of aerobics and weights 5 days a week and 3-5 softball games a week).
Water weight loss. A healthy weight loss should be no more than one pound per week.
The first 2 weeks of weight loss often happen at a much quicker rate than the subsequent weeks. Men, in particular, lose weight faster and more of it in the beginning - 10-12 pounds isn’t unheard of in the first week. When the rate drops (probably next week), it should be at an average rate of 1-2 pounds a week until you reach your ideal weight. Note that that’s an average - there will be some weeks you lose 3 or 4, and some weeks you won’t lose an ounce, and maybe even some where you gain a pound and want to smack yourself. Don’t, it’s all normal. As long as the average over several weeks is 1-2 pounds, you’re in the safe and most effective long-term weight loss zone.
Source: Weight Watchers meetings
What they said. When I started Weight Watchers I lost something like 6 pounds in the first week (I was a little over 200lbs at the time, 5’ 10", 36 year old male, fairly active). However you’re losing it, that 6 pounds isn’t going to be all body fat.
6 lbs of fat represents about 21,000 calories. If you were eating 3000 calories/day before and you dropped down to 2000/day, then you would still need to do something like 2 hours of vigorous exercise every single day (for example, running 16 miles) to hit that kind of caloric deficit.
If your activity level hasn’t changed much, I’ll guess that it’s a lot of water weight. If you stick with a sensible diet/exercise plan you may see a few more weeks of what seems like a lot of weight coming off but you’ll quickly come down to that 1-2lb/week rate which is the general recommendation for a healthy/sustainable loss until you hit whatever is a nice stable weight for your body. As WhyNot said, men do seem to lose more weight faster (at least in the beginning) than women. This is a source of endless amusement for couples who start a weight loss program together.
There is just something about simple sugars (simple carbs) and water as well as sodium and water.
Less carbs = body maintains less water. Further, less soduim = less water. Toss in a few real pounds of actual fat loss and a little less food in the gut and you can expect such results early on.
Look for 1-2 lbs per week thereafter, although 2 lbs of actual body fat is quite aggressive.