This post is written for the benefit of stumblers and newcomers The paleo way of eating is about optimising health
, and that's what we should all ultimately be aiming for. But the fact remains a lot of people start the paleo diet because they want to lose weight, so as we have a lot of new people on the forum these past few weeks (hi guys!) I thought I would write a little endocrinology 101
When I first started paleo I read quite a short, simple article online about insulin, carbohydrates and weight. I don't remember where it was but I do remember that as a person who knew little about the subject, it really clarified it for me and made me finally understnad why it is important to cut carbs to lose weight. So to help others, I will attempt to reproduce it!
The below is all very basic common knowledge for anyone who knows much about diet and biology, but not necessarily such common knowledge for the average stumbler starting out on the paleo diet.Part 1 - what happens in the body when you consume carbohydrates, a very simplified version
- Consumption of carbohydrates results in an increase in blood sugar. The more refined the carbohydrate, the faster and higher the rise
- Glucose is a fuel when it's in the muscles, but when it's in the blood stream in high levels it is essential a toxin
. Yes, a toxin.
- The body wants reduce the amount of this toxin in the blood, so the pancreas produces a load of insulin. Again, the higher volume and refinedness of the carb ingested, the more insulin is produced.
- Muscle cells are covered in insulin receptors; insulin binds to these and prompts them to take in glucose to remove it from the bloodstream. It is stored in the muscles as glycogen, to be used as energy when necessary (e.g. anaerobic exercise)
- if the muscles are 'full', the excess is converted into triglycerides and stored in adipocytes i.e/ turned into fat
. (this is why athletes, whose muscle cells have 'space', can eat a lot of carbs and not get fat. But they can still get diabetes on route to winning 5 olympic gold medals - see Redgrave, Sir Steve). -
- This is not a problem in and of itself, because the body is creating and burning fat constantly. However because of the spike in insulin, some of the glucose that was already in the blood
is also converted to fat as well. So you end up with slightly more energy stored as fat than the energy from the carbs you just ate.
- Additionally, this leaves you with low blood sugar and makes you more likely to snack or overeat, as you are hungry!Insulin sensitivity and Insulin Resistance
- if someone is described as being insulin resistant, this means that their muscle cells are not as sensitive to the effects of insulin and do not uptake glucose from the bloodstream so readily; the excess glucose is more likely to be stored as fat rather than stored in the muscle cells.
- this turns into a vicious cycle of the pancreas producing more and more insulin in response to the same carbohydrate intake. Diabetes and obesity are the eventual results.
- Someone who is insulin sensitive has muscles that are good at taking up glucose from the bloodstream. Exercise increases insulin sensitivity, as does intermittent fasting.How to lose weight on the paleo diet
- first one must understand that to lose weight, one must minimise the production of insulin
- rule 1 - every time you eat, insulin is produced. So to lose weight, eat less frequently, and don't snack
- rule 2 - carbohydrates result in the largest insulin response, followed by protein, followed by fat. So to lose weight, the intake of carbs (especially sugar) must be minimised and the intake of fat must be maximised. This is one of the many reasons why so many people on the forum will say 'eat more fat'. Remember that protein still has an insulinogenic effect - http://www.paleonu.com/panu-weblog/2010/1/11/insulinogenic-is-not-hyperglycemic.html
- rule 3 - anaerobic exercise uses glycogen for fuel and increases insulin sensitivity = less of the energy from your carbohydrate food will end up in fat cells, because it will either be burned, or taken into the muscles. It will also liberate body fats for use as energy, which can then be burned off via LOW INTENSITY aerobic exercise. Lifting heavy things is also crucial
- rule 4 - In terms of minimising the insulin spike, **Carbs from leafy green veg > carbs from roots and bulbs > sugars in fruit**
Paleo doesn't have to be very low carb
- you can eat 30/30/40 as carb/protein/fat or 5/30/65. But generally, the *less* carbohydrates (especially sugar)
you eat and the *more* fat you eat, the more easily you will loose weight.Paleo is not a weight-loss diet, it's a way of eating
Sidenote 1 - leptin
- Leptin is a hormone that inhibits the appetite. It is (mainly) produced in the adipose (fat) tissue
- Wheat germ agglutinin is a protein found in wheat and contributes to leptin resistance
- obesity results in overproduction of leptin and thus leptin resistance
- one who is leptin resistant does not feel 'full' so readily so is more likely to overeat
- this is one of the many why it is very important to cut out gluten grainsSidenote 2 - Fasting Induced Adipocyte Factor - simplified
(I believe the the below is still a theory rather than a fact)
- FIAF is another hormone, produced by the gut wall, liver and muscles.
- FIAF is mainly produced in times of starvation and prompts the body to burn fat by blocking the action of another hormone (lipoprotein lipase)
- active gut bacteria inhibit the production of FIAF
, inactive (hungry) bacteria cannot do this
- gut bacteria live on carbohydrate and fibre. They cannot 'feed' on fat and protein, become inactive, and stop blocking the production of FIAF
- for a proper explanation see http://high-fat-nutrition.blogspot.com/2007/12/fiaf-whos-fat-is-it-anyway.htmlSidenote 3 - hypothyroidism and hypothalamic amenorrhea
- Some some people, an extended period of time on a VLC diet can cause hypothyroidism
- the mechanism for this involves the leptin pathway - consistently low leptin causes the body to believe that it is starving and must conserve energy. Hypothyroidism results
- Tests will not show low thyroid because the overall thyroid levels often are not low. What is happening is that reverse T3 is not being converted to active T3; generally it will end up a T4 instead
- this is much more common in women than men, especially women who are not overweight
- symptoms include fatigue, coldness, dull hair and skin, reduced libido, irregular or absence of menstrual cycles, lack of weight loss despite a low calorie diet
- immediate introduction of more starch to the diet (e.g 80g-100g a day) should quickly bring things back to normal, if it does not, natural dessicated thyroid can be taken (other thyroid meds are not effective in this case)Sidenote 4 - adrenal fatigue
- a lack of cortisol production as the adrenal glands are exhausted by 'chronic stress'
- stressors do include low-calorie or low-carb diets, and/or frequent intense exercise without adequate recovery, injury, emotional stress, overwork, infections, drug/alcohol use (including prescription), sugar, lack of sleep etc.
- solution - a very clean paleo diet, absolutely no sugar or gluten, and a moderate amount of starch (50-150g depending on body size and exercise levels), sleep, reduce workload, sensible levels of exercise, elimination of any long cardio workouts
- unlike hypothyroidism this is not yet a medically recognised condition
1) Good Calories, Bad Calories, Gary Taubes