What is a Low-Carb Diet?

The term "low-carb diet" (also called "reduced carbohydrate", or "low-glycemic" diet) is a broad term, encompassing many popular diet books (Atkins, South Beach, Zone, Protein Power, Sugar Busters) as well as eating plans that don't follow a rigid format, but advise limiting the consumption of foods that are high in carbohydrate and/or are especially glycemic (raise blood sugar).

When you read the research about low-carb diets, "low-carb" is defined in many different ways. One difference is whether they are looking at the amount of carbohydrate in the diet or the percentage of calories from carbohydrate. The other difference is "how low?" The usual carbohydrate recommendations from the U.S. Dietary Guidelines and similar sources for the general public are that 50-65% of the calories in a person's diet should be from carbohydrate, so anything less than that is sometimes considered "low-carb". Studies of low-carb diets have ranged from 45% down to 5% , and authors of diet books are similar. That said, there are three general approaches:

Just reduce carbohydrate :-Basically, the thinking is that any reduction in carbohydrate is helpful, because increasing numbers of us have exceeded the amount of carbohydrate our bodies can easily handle. These approaches are mainly focused on reducing or eliminating added sugars and other refined carbohydrates. The "No White Foods" approach fits in this category, which means simply eliminating sugar, white flour, white rice, and potatoes from the diet.

Find the best amount of carbohydrate for each person :- There is no doubt that each of us has a different level of carbohydrate tolerance. We can think of this as a continuum from people who can eat sugar all day long with no ill effects all the way to diabetics with very poor glucose control. As we age, our carbohydrate tolerance often erodes and we have a greater blood glucose response to carbohydrate, even if our blood glucose stays in the "normal" range. We may develop insulin resistance or creep closer to prediabetes - these are signs that there is probably damage in the pancreas to the beta-cells which make insulin.

Seek a ketogenic diet :- A ketogenic diet is one which causes the body to primarily use fat for energy rather than glucose. (See What is a Ketogenic Diet?) This puts the body into a state sometimes called "keto-adaptation" or "fat adaptation". This state has some metabolic advantages such as improved stamina, e.g. since the body is used to using fat for energy, there is less tendency to "run out of fuel", either during exercise or between meals. One type of ketogenic diet is used to treat epilepsy, and ketogenic diets are under investigation to treat other disorders. Although there is some individual variation, a diet moderate in protein and below 60 grams of carbohydrate per day is ketogenic in most people. Some can eat as much as 100 grams per day and remain in ketosis.

Low-Carb Food Rules

Most of us carry around rules (or guidelines) about food in our heads. In fact, rules can be very useful when it comes to food selection -- imagine if we had to choose anew among the tens of thousands of foods in the grocery store every time we shopped! The important thing is to make sure your food rules are serving you, not working against you. Not only do rules simplify food choices, but as time goes on they can become part of your eating identity.

This carries its own momentum to help you continue to make wise choices. So what starts out as a conscious rule morphs into "just the way I eat", with little thought required. No more agonizing over the bakery section -- instead, you no literally longer care about the bakery section. Cookies just don't make sense any more. Here are some low-carb food rules to consider adding to your arsenal. Note that these rules aren't meant to be the be-all and end-all, just helpful guidelines. The very best rules are the ones you come up with yourself, that make sense to you.

Fats Are Your Friend

The Swedes have it right - I love the LCHF T-shirts I've seen them wearing. Low Carb High Fat! Yes! For many of us, this is the most helpful rule we can absorb. Most people in the U.S. carry around an unwritten rule that is the opposite of this - that fats are to be avoided. This is actually dangerous to your way of eating, because avoiding fats practically guarantees that you will eat more carbohydrate in their place. Of course, it's important to avoid unhealthy fats. Low-carb experts agree that avoiding trans fats and not overdoing the omega-6 fats (soy oil, corn oil, etc.) is vital to a healthy low-carb diet. OTOH, saturated fats are being found to not be the problem it was once thought, and lots of fat sources are really good for us.

Treat Sugar as Toxic

Although there are those who will argue that sugar is literally toxic, it isn't poisonous in the traditional sense. But for those of us whose bodies don't process sugars well, the effects of sugar in our bodies can be quite devastating over the long haul. For this reason, it can be helpful to think of sugar as toxic.

Avoid Foods Labeled Low-Fat, Gluten-Free, High-Protein, Etc.

Basically, labels like this are a) a signal that this is a manufactured food and therefore likely to be junk-filled and b) a signal of the priority of the manufacturer. These foods are usually high in sugars and refined starches. Even when the label is "low-carb" they can have a lot of suspicious ingredients that some people react poorly to (e.g. substances that are technically "fiber" in nature, but by the time they are installed in a processed food do raise blood glucose in many people). Caveat: As someone who must follow a gluten-free diet, there are a handful of foods labled gluten-free that I will eat, e.g. soy sauce. But the vast majority of the time, the gluten-free label means it's a high-carb food.

Before You Start a Low-Carb Diet

Before starting on any new eating program, it's important to do two things: 1) make sure you're prepared for what's ahead, and 2) take some measurements before you start, so you can know what changed.

Preparation to Change Your Way of Eating

Changing what you eat can be daunting, and most people don't succeed in making the adjustment to a different way of eating. Without preparation and support, the odds are not in your favor. Think carefully about whether you are motivated to do this, and make sure you have support (we have a Low-Carb Discussion Forum to help you with this). Then, do the steps in this Guide to Getting Started and check out How to Get Through the First Week. Make sure you have the types of foods you'll need. You can find help here:

a. Low-Carb Grocery Shopping List
b. Your Low-Carb Pantry
c. A Complete Guide to Cutting Carbs

Blood Pressure:- Blood pressure often responds quickly to a low-carb diet. If your blood pressure is high, you might want to track your blood pressure at home. (If you are taking blood pressure medication, be sure to tell your doctor about your diet, as it's very common for the amount of medication you need to change.)

Symptoms to Track :-It's a very good idea to keep track of symptoms you may have that often respond to a reduction in carbohydrate. You might just write a few paragraphs about your symptoms before starting your diet so that you will remember. It's very common for memory to fade about things like this. Also, any gastro-intestinal symptoms are good to make note of. More than one person has serendipitously found out about food allergies or sensitivities when changing their diet. Things to pay attention to include energy level, mood, ability to concentrate, heartburn and other GI symptoms, allergy symptoms, compulsive eating, joint or muscle pain, PMS symptoms, acne and other skin problems, and headaches.

I wish you all the best on your low-carb journey! Sign up for my newsletter, and find out the latest things I'm writing to help you along the way, along with recipes, food ideas, the latest science, and lots of tips.