Fat Jimmy

Jimmy Moore is a prominent advocate of the Low Carb/High Fat diet and lifestyle. Jimmy Moore is presented as proof that the Calories-In/Calories-Out model is correct and that obesity is not hormonal. Jimmy’s hormones are said to be entirely in order, but Jimmy is still fat.


I am not publishing this to shame or ridicule Jimmy but to look at reasons that Jimmy might still be obese as well as offer some possibilities for helping Jimmy with his obesity.

Jimmy’s Weight Loss History

Jimmy is no stranger to weight loss nor self discipline. Jimmy has written that he previously lost 170 lbs in nine months using the Low Fat diet (SATURDAY, DECEMBER 24, 2005. Low-Fat: Been There, Done That, Made Me Fat. Jimmy Moore.). Jimmy says his starting weight (before the Low Fat Diet) was 410 lbs. Jimmy stated that he regained the weight and got “above 400 pounds towards the end of 2003”.

Jimmy goes on to state that found Low Carbs and he lost 100 lbs in his first 100 days on Atkins and that he went on to lose a total of 180 lbs in that year (by the end of 2004). So that would put Jimmy at about 240 around Jan 2005.

Jimmy’s own biography on his website has many photos which show Jimmy at many different weights (Meet Jimmy) and here (Before & After) with the most recent being 2012 (chest up).

Jimmy’s Current Weight/Health

I do not know Jimmy’s current weight. What seems clear is that Jimmy has lost a lot of weight and kept much of it off. But I will concede that I have seen recent pictures of Jimmy and he is still fat.

Jimmy has tried various hacks such as Extended Fasting (Link) to lose weight and they don’t seem to be all that effective.

Most importantly, Jimmy’s claim is that he is now healthy (off medications, etc). Jimmy has posted blood sugar numbers as screenshots so I believe he is healthy (as far as diabetes and blood sugars).

Jimmy did post one weight loss chart on his page (ending ca May 2013) which correspond to a food elimination diet to see why he was still fat.

Jimmy’s Hormonal Profile

The claim is Jimmy has low resting Insulin rates. (Updated Jimmy has since confessed that his fasting Insulin is more like 14 – about 19:40 into the program). Assuming Jimmy adheres to the Low Carbohydrate diet he probably does. The counter-claim is that since Jimmy is fat it is proof that the Carb-Insulin-Obesity hypothesis is false. The problem is that it oversimplifies hormones and reduces them to a single hormone.

I’ve never seen a copy of Jimmy’s hormone test results, but the fact that Jimmy is overweight implies that he has excess female hormones (they come along with obesity) and a lack of sufficient male hormones (they come along with leanness). Jimmy’s insulin levels may be OK, but Jimmy probably has messed up sex hormones (part of the hormonal profile).

Helping Jimmy

imbalances in the hormone Insulin aren’t the only cause of obesity. There are a lot of food/hunger related hormones. Jimmy has done a number of shows focused on Leptin (example: Dr Rosedale who views Leptin disorders as the cause of diabetes not Insulin).  Jimmy’s answer to obesity could still be found in a hormonal disorder.

The hormonal-obesity theory rather than the insulin-obesity theory may provide some insights to what could help Jimmy. From (Obesity and hormones):

Hormones are chemical messengers that regulate processes in our body. They are one factor in causing obesity. The hormones leptin and insulin, sex hormones and growth hormone influence our appetite, metabolism (the rate at which our body burns kilojoules for energy), and body fat distribution. People who are obese have levels of these hormones that encourage abnormal metabolism and the accumulation of body fat.

A system of glands, known as the endocrine system, secretes hormones into our bloodstream. The endocrine system works with the nervous system and the immune system to help our body cope with different events and stresses. Excesses or deficits of hormones can lead to obesity and, on the other hand, obesity can lead to changes in hormones.

I’d like to see Jimmy look harder into other hormonal possibilities being the root cause of his continued obesity. If Jimmy has exhausted the hormonal tests, that would be worth knowing.

Fat to Satiety

Jimmy eats “Fat to satiety” (Link) but what exactly does that mean to Jimmy. Leptin is a hormone that controls hunger. As an example there’s something called Leptin receptor deficiency which causes obesity. Maybe Jimmy satiety mechanism is broken?

Jimmy Doesn’t Count Calories

To make the claim that Jimmy disproves the hormonal-insulin-obesity model it is necessary to know just how many calories a day Jimmy consumes. After all, since Jimmy is still fat he must be overeating calories, right? But Jimmy doesn’t count calories. Nor does Jimmy publish food diaries so it’s speculative to guess how many calories a day Jimmy eats.

I’d challenge the advocates of Calories-In/Calories-Out to publish Jimmy’s food logs. Otherwise, they are begging the question they are attempting to prove (question-begging fallacy). It could very well be possible that Jimmy eats relatively low calories but is still obese due to a metabolic disorder (other than insulin related).

Missing Protein

An important part of Jimmy’s Low Carb lifestyle is relatively low protein. So the problem may be that Jimmy just doesn’t get enough protein. Again, without a food log it’s impossible to know what Jimmy is eating.

Low Carb/Low Fat (Protein Sparing Modified Fast)

Jimmy has written that it is bad to do both low carb and low fat at the same time. This diet is the Protein Sparing Modified Fast. It’s pretty clear that Jimmy has not tried both at the same time. Added to Jimmy’s self-imposed limit on protein consumption it’s pretty likely that Jimmy has not ever tried this hack.

Jimmy didn’t like Low Fat diet because he was always hungry on the diet. What Jimmy is missing is that the hunger was due to his continued consumption of carbohydrates. If a person is doing low carb then low fat is also possible without feeling hungry.

Jimmy could try one of his famous n=1 experiments and do PSMF for a few weeks. I believe Jimmy would adapt and do pretty well on the diet.

(2018-05-04 Jimmy did PSMF – here’s my view of what he did).


(2018-06-05 CarbSanity – Jimmy Moore — Big Fat Liar — Steps in it AGAIN! It Was NOT a Joke, He Is!)

Author: Doug

I'm an Engineer who is also a science geek. I was pre-diabetic in 1996 and became a diabetic in 2003. I decided to figure out how to hack my diabetes and in 2016 found the ketogetic diet which reversed my diabetes.

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