What's Causing Your Weight Gain?
I once had a client who, after working with me for about a month, nearly stabbed me with my body fat calipers. The reason? She had actually gained weight rather than losing it, which, as you can imagine, wasn't our primary goal. While I'm sure many of my clients fantasize about stabbing me (a good reason never to give out my home address), gaining weight after starting an exercise program is something many people experience.
The reason for this weight gain is usually related to the calories in/calories out equation - namely, more calories are going in without them realizing it. That's what happened with my client who, after keeping a food journal, realized she was eating more at her meals than before she started exercising. It was a good thing we found that out before she became physically violent.
There are other reasons we may gain weight including:
- Overstimating calories burned - This is easy to do, especially if you're relying on cardio machines, which aren't always accurate. This is particularly problematic when you're relying on those numbers for weight loss. If a machine tells you you just burned 500 calories, but you really only burned 200, it's easy to miscalculate your calorie needs and overeat.
- Eating too much - Like my client, it's easy for new exercisers to overcompensate for their workouts by eating more. Keeping a food journal can help keep you on track.
- Relying on the scale - When you start exercising, you may lose body fat, which isn't always reflected on the scale. You may be making progress without even realizing it.
- Medical conditions or medications - If you're on certain medications or have a condition, such as thyroid problems, it may be more difficult to lose weight.
There are a number of other areas to look into if you're gaining weight and you can find out more in what's causing your weight gain.
In my experience, weight gain is almost always caused by eating too much, but what about you? Did you gain weight after you started exercising? What was the problem and how did you deal with it? Leave a comment and tell us about your experiences.


Another reason for weight gain can be muscle gain. Especially if one engages in a lot of weight lifting routines.
In my 4 yrs of weight loss pursuit I had plataued at 240, then I did a 12 week weight lifting program, which helped burn a large amount of fat only, also added 10 lbs to the scale in muscle.
We had a competition at work for weight loss and while I did not lose any weight I did lose inches during the 3 month competition and at some point in your pursuit to lose weight or become more fit it has to become less about the number on the scale and more about the measurements of your chest, waist, hips, etc and how your clothes feel because the scale does not give a true breakdown of body composition.
I used to work at a weight loss center and another reason some people gained weight at first was their water intake. They started eating healthy foods, exercising, and drinking 6-8 glasses of water per day.
I was doing lots of exercise to lose weight. My measurements went down more than my weight because the fat was going but muscle was increasing. Muscles weigh more than fat.
I’ve been doing cardio for 1-3 miles a day, 4 days a week, and toneing exercises and weight 3 days. I have been doing this for one month. I am 5′9”, weigh 250 and am on a 1200 calorie diet each day. Have not lost but ONE pound….but I look toned and can really tell a difference in my thighs and arms..but I still want tht scale to move
I manage to keep my weight very consistent. A simple rule is that I can eat as much fruit and vegetable as I want, and avoid animal fat.
One thing that was a big factor in heading in this direction was counting calories in and out. I searched for a good piece of software or website, and found many. The best one I found is the US government one provided here:
http://www.mypyramidtracker.gov/login.aspx (this is the login page but I am sure you can get where you want to go if you are interested). IT is complex, gives nutrient and vitamin feedback. Worth a try. I try to follow this religiously about every 6 or 8 months for about 4 weeks, just to make sure I am on track.
“Weight Gain”. Muscle or fat? There is drastic difference. As a certified fitness trainer of 15 years, one learns that relying on the scale is inapprorpiate. If a client is engaged in strength training as well as cardiovascular training, there may be an initial loss of “weight” as indicated by the scale. However, muscle tissue weighing more than fat tissue, a client may indeed gain more “weight” via muscle tissue increasing. With this should also be a loss of fat tissue if training is being done correctly….this is “Body Contouring”, and, YES, it may very well come with a gain in “weight” as explained. This is why “weight loss” is an inappropriate term and the scale is an inappropriate means to measure progress.
Robin- I work as a workout nutrition advisor and want to praise you on your hard work and dedication. I might sound crazy, but if you are working out as you say you are and only eating 1200 calories, you are not feeding your body enough fuel to lose weight. By eating so little, you are putting yourself into starvation mode. If you up your calorie intake by a few hundred calories, you will prob see some weight drop off. Also, make sure you are switching up your workouts every 4-6 weeks, otherwise you will plateau.
My problem may sound individual, but it might cause a few people to ask their doctor to check their thyroid levels. I was diagnosed with thyroid cancer at 135 lbs. I had been more tired but continued to exercise without wt gain. Then I had to have the thyroid removed. 6 months later, I had gained 20 lbs. SO FRUSTRATING because I dont know the answer!! I PUSH to exercise but remain tired. My TSH and T3, T4 levels have not come to normal as my Synthroid levels are changed up and down. But I continue to gain wt and remain tired. My endocrinologist says she might give me diet supplements but my thyroid levels have to be normal for 6 months, first….My new philosophy is “Mind over Matter in a BIG way!” I am going to make sure that I get at least 30mns cardio, 20 mns wts and keep a more focused higher protein food diary. If you have suggestions, please let me know! Thanks!