Any lawyer who lived through the '80s and '90s was hit with a barrage of messages from the government, nutrition “experts” and big consumer brands that dietary fat was the devil. We pointed the finger at fat as the cause of obesity, heart disease, diabetes and other nasty health issues. And thus began the rise of the low-fat diet craze (SnackWells, SlimFast and Baked Lay's—Oh my!). You probably had some in your desk drawer at one time or another.

As part of the craze, food manufacturers stripped products of fat, and, to keep them tasty and appealing, they replaced it with carbohydrates from sugar, refined grains or other starches.

Turns out we cut off our nose to spite our face. Our bodies digest these refined carbohydrates and starches very quickly, affecting blood sugar and insulin levels and resulting in the dreaded weight gain and disease.

Current research confirms that “healthy fats” are actually quite necessary and beneficial, and, in fact, you should eat them daily, counselor. Several important vitamins (like A, D, E and K) require fat to dissolve so they can be used by our bodies. Fat is needed to build cell membranes, the vital exterior of each cell, and the sheaths surrounding nerves. It is essential for blood clotting, muscle movement and inflammation. There is also some compelling evidence that it can improve body composition, help fight cancer, preserve eye health, preserve memory and reduce ADHD symptoms.

But you also should continue to avoid certain “bad fats.” And to make it a little more confusing, some fats fall in the “middle” and need to be eaten in moderation. So let's clear things up.

First, understand that fats are organic molecules composed of carbon and hydrogen elements joined together in long chains called hydrocarbons. The terms monounsaturated, polyunsaturated, saturated and trans refer to their chemical bonds, and the molecular configuration determines whether fats are healthy or unhealthy.

Monounsaturated fats are found in a variety of foods and oils like olive oil, avocados, groundnuts and tree nuts. Studies show that eating foods rich in monounsaturated fat improves blood cholesterol levels, which can decrease your risk of heart disease and may also help decrease the risk of type 2 diabetes.

Polyunsaturated fats include Omega-3s found in flax and fish oil and Omega-6s found in most seed oils like canola, safflower and sunflower. Eating foods rich in polyunsaturated fat improves blood cholesterol levels, which can decrease your risk of heart disease and may also help decrease the risk of type 2 diabetes. Many nutritionists recommend daily algae or fish oil supplementation.

Common sources of saturated fat include red meat, whole milk and whole-milk dairy foods, cheese, coconut oil and many commercially prepared and processed foods. “A diet rich in saturated fats can drive up total cholesterol, and tip the balance toward more harmful LDL “bad” cholesterol, which prompts blockages to form in arteries in the heart and elsewhere in the body. For that reason, most nutrition experts recommend limiting saturated fat to under 10% of calories a day.

The worst type of dietary fat is the kind known as trans fat. It's a byproduct of a process called hydrogenation that is used to turn healthy oils into solids and to prevent them from becoming rancid. Trans fats have no known health benefits and there is no safe level of consumption. Thankfully trans fats have been officially banned in the U.S. and as of June 2018 manufactures may no longer include them in products. Some trans fats do occur naturally like CLA and may actually be beneficial to health.

So as long as we avoid trans fats and eat saturated fats in moderation, we can eat as much healthy fat as we want? Right? Not exactly. Healthy fats are amazing, clearly. But they are high in total calories. And even if we're eating super nutritious foods, if we eat more calories than we need, the excess will be stored as body fat and can lead to health problems.

That's why it's important to have a sense of what your caloric needs are and to establish a lifestyle that supports them, always a challenge for busy lawyers, I know. I'm a fan of what's called “flexible dieting” to achieve this. For more on that you can read my free guide at www.JJ-Fit.com/freeguide.

Jonathan Jordan is a personal trainer, nutrition coach and corporate wellness consultant in San Francisco. Check out his blog JJ Fit 24/7.