The Biggest Loser show – 34lbs lost in ONE week? Really!?

The 9th season of the Biggest Loser show on NBC started on Jan 5th and had its first “weekly” weigh-in at the end of the show. One of the contestants, Mike, lost 34lbs. First, that is great that Mike lost this amount of weight. However, when you do the math the numbers just don’t add-up. Basically, as you will see below, it is almost impossible for a person of Mike’s size (524lbs) to lose 34lbs in one week.

The following is the breakdown.

First, I subtracted 10lbs of the weight loss as pure water (a rough estimation and likely on the high side)

That leaves a 24lb lose of fat (probably not only fat, but some lean tissue also)

Divided by 7 days = 3.4 lbs a day

The caloric amount of 24lbs of fat equals approximately 84,000 calories (1 lb fat ~ 3,500 calories)

Therefore, to lose 24lbs of fat, Mike would theoretically have to have a deficit of 84,000 calories for the week.

Could this happen in a week? Not likely.

Mike’s approximate BMR is 4,066, meaning he will burn this amount of calories everyday without exercise.

His total calories for the week from his BMR ~ 28,462 calories

Total calories needed to burn to lose 24lbs of fat ~84,000

Total calories burned for the week from his BMR ~ 28,462

That leaves a balance of ~ 55,538 calories that still needs to be burned from exercise

Keep this in mind; at no point do I have Mike eating anything. He is not consuming any calories!

Let’s divide the 55,538 calories by 7 days to see how many calories Mike would have to burn per day from exercise

That results in 7,934 calories a day that needs to be burned from exercise per day

To burn that amount of calories a day, Mike would have to do ~ 5 1/2 HOURS of moderate cycling each day. Remember, he is doing this and NOT eating anything and most likely out-of-shape.

The numbers just don’t add up and I took out 10lbs for water loss. What I think is happening is that the time frame is 10 to 14 days. What really bugs me is the lack of transparency with the Biggest Loser show. Why not give specifics on exactly how much the contestants are eating and exercising and what the real time frame is between weight-ins? I am glad that people are losing weight, and a lot of it, but it gives the false impression if the details are not correct or available. I do not intend to be so negative, but until a logical explanation is given I will content that there is likely something fishy going on.

Additionally, the clinical research that has been done on very low calorie diets and complete fasting of very obese individuals does not support that this amount of weight loss will occur this quickly. Two particular studies are very relevant to this subject matter.

The first study was done in 1968. A 450 lb man went on a medically supervised fast (means he did not eat any food/calories) for 1 year and 2 weeks and lost 245 lbs and had no major complications (Stewart et al, 1973). This would average about 4.7 lbs a week, which is nowhere near the 34 lbs that occurred with Mike who started at a weight that was fairly close. Yes, Mike did some exercise and the person in the study did not. But, as discussed earlier, the amount of exercise to attain this type of weight loss is very high.

Another study, just published last year, followed 5 obese individuals (average weight of 469lbs), in an in-patient setting, for 11 weeks, that were eating a bit less than 900 cal/day and exercising 30 minutes 1-2 days a week lost on average 7.72 lbs a week (Huerta et al, 2009). The rate of weight loss was fairly consistent. These results from a very controlled study also do not support such a large weight loss depicted in one week from the Biggest Loser contestant Mike. What these results tell me is that the spectacular weight loss of 34lbs in one week is highly suspect. Again, I am glad that Mike and the other Biggest Loser contestants are losing weight but I would really like to know how they can do this.


Stewart, W.K. & Fleming, L.W. (1973). Features of a successful therapeutic fast of 382 days’ duration. Postgrad Med J; 49: 203-209.

Huerta, S. et al (2009). Feasibility of a supervised inpatient low-calorie diet program for massive weight loss prior to RYGB in superobese patients. Obes Surg; DOI 10.1007/s11695-009-0001-x.

The Biggest Loser Show – Very Misleading!