Obviously, if you want to lose weight, you need to "burn" (metabolize) your fat stores and the common wisdom is to eat less and exercise more. If you don't succeed, you're obviously lazy and not trying hard enough. However, this is supremely poor advice because it neglects your body's endocrine system, which heavily affects its metabolic state: fed or fasted. Your pancreas produces many hormones but the one that determines its metabolic state is INSULIN. The FED state is characterized by high insulin while the FASTED state is characterized by low insulin. One of insulin's jobs is to regulate blood sugar (ie, serum glucose) and the macronutrients (carbohydrate, protein, fat) in your meal have a huge effect on serum glucose. The Randle Cycle describes the process the body uses to determine whether it is the fed or fasted state.
Besides determining the metabolic state, insulin has a major effect on the body's ability to shed weight because insulin is THE fat storage hormone. When insulin is elevated, Lipoprotein Lipase (LPL) is activated which splits Triglyceride (TG) molecules into glycerin and fatty acids to allow fatty acids to diffuse into the fat and muscle cells. Insulin also activates the GLUT4 transporter, which is the gate through which glucose enters fat and muscle cells. When insulin is low, Hormone-Sensitive Lipase (HSL) allows fat cells to release TG back into the blood stream. The net result is that you MUST have low insulin to lose weight. Long-term caloric restriction (ie, eat less, move more) causes two more insults to dieters: 1) LPL becomes much more active when insulin is elevated, thereby making fat cells better at growing and 2) Ghrelin and Leptin (hunger hormones) also become more active. The more and longer you increase the caloric deficit, the hungrier you and your fat cells become. Low insulin inactivates LPL and actives HSL. In addition, low insulin levels increase LPL activity in muscle cells, thereby helping them to shift to fatty acid metabolism.
- Dr Paul Mason: Fat Cell Growth
- Weight reduction increases adipose tissue lipoprotein lipase responsiveness in obese women
- Calorie-restricted weight loss restores ghrelin sensitivity
- Appetite hormones may predict weight regain after dieting
Carbohydrate is the only macronutrient that contains sugar and this can take the form of monosaccrarides (ie, glucose, fructose, galactose) or disaccharides (ie, lactose, maltose, sucrose) or starches (long chains of glucose). Since your body tries to tightly control serum glucose, insulin is used to store excess in muscle and fat tissue. Protein isn't really a fuel (unless you're starving) and your body primarily uses protein to maintain its structure. Depending upon the type of ingested fat (short, medium, or long-chain), your body will either preferentially metabolize it or store in fat tissue and fat elicits a much lower insulin response for storage than glucose. Your microbiome ferments soluable fibre carbohydrate into short chain fatty acids but, with a rudamentary cecum (appendix), humans evolved away from herbivory. Unlike most natural foods, dairy is the one food group that contains all 3 macronutrients and is beneficial for growth in children. Lactose (milk sugar) definitely raises serum glucose, which will shift the body to the fed state. To minimize this effect, fermented full-fat dairy products (cheese, yogurt, etc) are a better alternative to milk in adults because of reduced sugar content. Fermented foods are generally beneficial because bacteria have converted sugars into short chain fatty acids.
In order to maintain a low insulin level, the obvious thing to do is minimize carbohydrate consumption and those on a carnivore diet avoid carbs completely. This is contrary to government food guides but there are NO essential carbohydrates - only essential proteins and essential fats. "Essential" means that the human body cannot synthesize these nutrients itself and requires their consumption. If you don't eat carbs, you still need to maintain your body's caloric requirements so you need to get fuel from another source, which is fat. Although some tissues in your body absolutely require glucose (ie, red blood cells and some brain cells), your body has the ability to manufacture ALL of the glucose it needs on demand from adipose tissue (fat cells) via gluconeogenesis in the fasted state. Fat is also converted to ketone bodies (acetoacetate, beta-hydroxybutyrate, acetone) in the liver via ketogenesis and the brain readily switches over to ketolysis when ketones are available.
Processed foods are typically made in factories by industrial processes and characteristically contain high amounts of carbohydrates and fats [usually in the form of industrial seed (vegetable) oils]. Besides the obvious high caloric content of processed foods, highly processed foods cause a much higher insulin response than those foods in their whole-food form due the disruption of their cellular structures. A food's fibre content is more of marker of its degree of processing than its nutrition so added fibre is NOT beneficial. Vegetable oils also play a huge role in cardio-vascular disease, especially when they become oxidized from heating. Basically, if the food is manufactured, don't eat it - no matter how healthy it says on the label.
- Gabor Erdosi: Part 2 of 2 - Insulin, Incretins - and the Perils of Processed Food Carbs
- Dr. Michael Eades - 'Incretins, Insulin, and Food Quality'
One of insulin's many effects is causing the kidneys to retain salt. When lower insulin levels, your body will excrete more salt with an accompanying decrease in blood pressure. If you're on hypertensive drugs, you may need to get your doctor to adjust your medication to prevent hypotension (low blood pressure) and you may also need to consume more salt to prevent the "keto flu" (fatigue, brain fog, headaches, muscle cramps, etc). Adequate salt consumption is necessary for good health so don't be afraid to add salt according to taste or have a glass of salty water if you're having keto flu symptons. Adequate potassium intake is important and potassium-enriched salt may be helpful. Cutting salt intake is ineffective at lowering blood pressure and it tends to worsen insulin resistance. The net result is that cutting your salt intake could worsen your diabetes, which implies that insufficient salt could elevate insulin. Again, only make electrolyte changes under the supervision of a doctor.
- Dietary Sodium Restriction Impairs Insulin Sensitivity in Noninsulin-Dependent Diabetes Mellitus 1
- Effect of potassium-enriched salt on cardiovascular mortality and medical expenses of elderly men
- Insulin resistance and hypertension: new insights
- Urinary Sodium and Potassium Excretion, Mortality, and Cardiovascular Events