Low Carb, High Fat Diet: Getting Started

By Peter Jensen, MD, Medical Director of Hospitalist Services, Marion General Hospital

Why restrict carbohydrates rather than total calories or fat?

In a nutshell: it’s about insulin. Insulin has two main functions:

1. It enables glucose to enter cells so they can utilize it for energy
2. It promotes the deposition of fat into the body’s fat stores

The higher the insulin level, the more fat is deposited and locked into fat stores. Carbohydrates are the primary food type that stimulates insulin release. Eating foods very high in sugar and refined carbohydrates causes significant spikes in insulin levels, which not only causes more storage of the food you just ate into fat, but also adversely affects your liver and muscle tissues over time. As a result, these organs become resistant to insulin. This insulin resistance then requires the pancreas to secrete more and more insulin to overcome the resistance, which leads to higher and higher insulin levels, which leads to more and more deposition of fat into fat cells, resulting in obesity as well as metabolic syndrome… which entails diabetes, hypertension and vascular disease (i.e. heart disease and stroke).

Eventually, the pancreas is no longer able to keep up with the ever-increasing insulin resistance in the liver and muscle, and sugar levels start to rise, causing diabetes. The only way to reverse this process and get insulin levels reduced to the point where they no longer keep fat locked into the fat cells is to lower the primary food type that causes insulin to rise: carbohydrates. If carbohydrates are removed from the diet or drastically lowered, the insulin levels begin to fall, eventually to the point where fat is no longer trapped in fat cells and is released into the blood, where it is available to be used by the body for fuel.

Your brain can’t tell if this fat in the blood came from fat stores or something you just ate. This is why you aren’t hungry on a low carb diet. Weight loss results. In diabetics, this weight loss improves insulin sensitivity, resulting in improvement and often reversal of diabetes. Basically, with a carbohydrate restricted diet, you are reversing the basic causes of obesity and diabetes. Years of eating foods high in carbohydrates, with resultant high spikes in insulin, causes the development of insulin resistance, which leads to chronically elevated insulin levels and resultant metabolic syndrome and diabetes. Cutting carbohydrates reverses all this.


Limit all sugar: sweets, desserts, sodas, sweet tea and juice, all juice! Liquid sugar (i.e. sugar sodas and juice) are absolutely the worst offenders in causing obesity and diabetes. Fructose, which is half of the molecule sucrose (table sugar), is a main cause of fatty liver.

Limit starches and starchy vegetables: bread, potatoes, rice, noodles, corn, grains, flour, beans (baked, butter), peas, grits, cereal, fruit (yes, fruit), and milk.

What you can eat: meat, eggs, cheese, nuts (1 to 2 oz per day) and “green vegetables” (i.e. broccoli, cauliflower, collards, okra, cabbage, squash, lettuce, tomatoes, string beans, onions, mushrooms, olives, pickles, etc.).

It’s called low carb, high fat for a reason. You replace carbohydrate calories with fat calories (not protein). This diet keeps you in ketosis for enhanced weight loss and performance, as well as cancer fighting properties. Add butter to vegetables and dry meats instead of gravy, which contains flour. Cook collards and turnip greens with ham hocks, fat back, pig tails, and bacon grease like your grandmother did. Eat regular meat and regular ground beef, not lean.

It is okay to fry food in healthy fats like lard, butter (grass fed if you can afford it–not margarine), beef tallow, (again like your grandmother did) or coconut oil rather than artificially processed vegetable oils like corn, safflower, soy and canola. The vegetable oils (with the exception of olive and coconut), are high in omega-6 fats and can be harmful.

Grass fed beef and dairy is best. These are higher in omega-3 oils and vitamin K2, and are more natural.

Milk contains carbohydrates (namely lactose), so it needs to be limited. If you do drink milk, make it whole, not reduced fat. Fat free milk causes far more weight gain than whole milk.

Yogurt is made from milk, and the label will list the carbohydrate content of the milk it was made from, which is about 11 to 12 grams per 8-ounce serving. However, yogurt is made with active bacterial cultures, which ferment the lactose into lactic acid, hence, the bitter taste. As a result, the carbohydrate content in yogurt is not equal to that of the original milk.

What about alcohol? Beer: way too many carbohydrates; wine: better, but needs to be limited; hard liquor: okay, there are very few carbohydrates in hard liquor.

What about diet drinks? It is best to limit these as well. The brain senses “sweet” and sends a message to the pancreas to release insulin and the insulin then drives ALL the calories you just ate (carbs, fats and proteins) into your fat stores. It’s best just to drink water.

Try to keep total carbs or at least net carbs (total carbs minus total grams of fiber) under 20 grams per day.

Test urine daily with urine ketone strips to be sure you are in ketosis, which usually correlates with weight loss.