No weight loss for over 3 weeks

Running is great, keep doing it! I feel a million times better since I started running. But make sure you're mixing it up - definitely do weights if you aren't doing any already. Personally, I like compound exercises that work lots of things at once (good time-saver).

Mostly I think it's diet though. Sugar is a killer, I'd highly recommend dropping the Lucozade in particular. It's just awful stuff. If you need a boost before working out go for something with some nutritional value. Protein powder is also high calorie for what it is, and unless you've just had a heavy weights session I'd say drop it and go for chicken or fish. Real food is always preferable to supplementation.

Get more veg too. Assuming it's not deep fried, you can't really go wrong with upping the veg.

First, it isn't a race. Yes, we like to see progress every week and we like to see it fast, but what we like and what actually happens are two different things.

It isn't unusual to have a fairly rapid loss that meets our schedule and then suddenly have very little happen on the scales. Stop focusing on the weight.

The weight is the symptom, not the problem (and it probably did not just happen overnight).

Second,you could have some inital weight loss that is a combination of water, fat, and yes, muscle loss. But when we get active, the muscle loss will be pretty short-lived because your body is scrambling to figure out what happened. Why the change (all of a sudden) is what your body is wondering. It was in some other equilibrium and you changed that. And it may fight you to keep doing what you had been doind and maintaining that weight. Evidence suggests this is what happens with a large decrease in calorie consumption to trigger weight loss even if it is accompanied by physical activity.

Third, given your diary it could be that you are on a muscle build given how much protein you seem to be consuming. Yes, I have friends that swear by protein supplements and I know there are some studies that show that a slight increase in protein after workouts and now seemingly more importantly just before bedtime may help muscle repair and burn rates. But then again, they workout at the gym with weights on a rotation program for different muscle groups and I'm more of a cardio guy. But I can run up the 5 floors in our building and not be straining to breathe and they are huffing and puffing.

Lean.

Fourth, take a look a look at what you are drinking. Yes, I know I drink coffee. I have cut back my sugar and cream intake and have given up the flavored creamers. But I have given up carbonated drinks. Just lost my taste for them as a caffeine, phosphoric acid, carbonic acid and sweetener delivery system.

Finally, my weight loss was a relatively straight line at first but then was a series of plateaus with fairly dramatic drops after several weeks or months even though I kept doing what I was doing. Even though my weight wasn't changing (remember it is a symptom), other measures such as how my clothes fit, my physical endurance, etc. were changing. I had a one year long plateau in 2011 where I just kept going even though my weight really did not move. But my clothe sizes were...down 4 inches in pants waist size, down another inch in neck size, moving from a L/XL size (depending upon which piece of clothing we are talking about) to the point where L was really too large.

This year was the final drop with a very small adjustment in physical activity and adjustment of food intake.

Yup get a HRM I bet you are overestimating your calorie burn!

It's possible you are adding muscle and losing fat, which would keep your weight about the same. Take measurements!

I took a look at your food diary, and I have some suggestions. I hesitate to critique anyone's habits and diary, but since you asked here are my thoughts. I suspect you are over-estimating your calories burned at the gym. I read your comment about how you estimate the calories burned, but I suspect something is off in the calculations. Unless you are working for 1.5-2 hours, I doubt you are burning 900-1100 calories.

Some other thoughts:
- I noticed that you drink a lot of diet soda. I used to do that too and I didn't lose any serious weight until I stopped.
- I would suggest more water, fruits and vegetables and see if you notice a difference.

Again, I hesitate to comment on anyone's diary, please do not take any offense. Good luck!

Diet soda is actually worse for you than regular. Fewer calories, but it takes a huge toll on your body. The sweeteners make your pancreas produce insulin to digest sugar, regardless of if it is sugar or not. This leads to insulin resistance and in the long run diabetes. Also: The sweeteners are really crap for your cells. It ruins the fluid balance in the cell. This does not happen for sugar. (Just "food for thought").

Also, I think you may have included exercise twice in your TDEE-approach. 3200 sound really high, even if you are heavy, at sedentary level.

Dingle,
Try this.
Get your carbs/sugar down and shoot for 150g of net carbs a day. (Carbs minus fiber). Start measuring fiber and shoot for >30g per day (I saw almost zero in your one diary day I looked at). Sugar should be more like 35g than 135g per day. That will happen automatically if you are <150g of net carbs per day. Sodium, have a look at that as well for <2500g a day.
On exercise, your cardio could be actually working against you, burning up carb calories, not fat, in a crappy cycle of carbs out, carbs in. Try exercising in a HR of 55%-75% of your maximum HR and you will burn fat. Believe it or not, just walking burns more fat than sweating your you know what off on a treadmill. Keep lifting weights.
I know this stuff works and hope it works for you. Good luck. Have Fun. It will happen.
Signed,
Much Older Guy

Here is a did you know to get you thinking. I want you to look at your food log after you read this and tell me if anything pops out at you. Here we go:

Did you know that when sugar enters you system fat storage stops and fat storage begins?

I used to drink a lot of "full fat" sugary drinks, I'm trying to cut down on those, I've switched to diet versions and I'm trying to add more water by alternating the drinks.

Diet soda actually confuses your brain to think your getting sugar when in fact you are not. What does that do you ask? Good question...makes you crave sugar. Drink Water!!! Lots and Lots of water. Start with a gallon a day.

(Option 1-Physical activity advice)
You currently hold high emphasis on cardio. Yes it burns calories, but also burns through muscle. Try changinge things up by reversing your workout. Instead try

10 minute cardio warm up (light jog)
45 minute compound weight training
15-20 minute run

The weight training will boost your metabolism, and the15 minute cardio at the end will compliment the fat burn without risk of burning into muscle.

(Option 2)
Run-Sprint Intervals 20 minute sessions. 3 times a week with regular weight training inbetween.

(Option 3)
Carb cycling (google) with combined exercise. this one takes strong commitment and dedication. I myself always lose weight when I attempt to master it. But I can never get past more than 3 cycles
Not convinced on the weight training than try