When you’re in the process of losing weight, it’s important to remember that the extra weight didn’t just come about overnight, and in the same manner, it will take some time to lose it. Patience is important—hard, but important—because anything that happens super rapidly simply won’t last. Fortunately for some people starting a vegan diet, less patience may be required than for other diets. Some people find that when they start a vegan weight-loss regime, excess weight begins to drop off quite literally overnight.
Experts agree that safe weight loss generally occurs at the rate of 1 to 2 pounds per week. However, depending on how you were eating before switching to a whole foods, plant-based diet, weight loss can be more dramatic on a vegan diet, especially as your body goes through the introductory period, usually lasting anywhere from two weeks to a month, of ridding itself of toxins and substances that have built up and clogged the body over the years from eating a diet heavy in animal products and/or processed foods.
In some instances, people initially lose as much as 3 to 4 pounds per week before leveling off.
One of the first things you’ll notice will of course be looser clothing. Within a few weeks, the weight loss will be visible both to you and to others. These noticeable results are great motivation, and the relatively rapid pace of loss will help you reinforce your commitment.
A 2005 study by Dr. Barnard and other researchers, which measured the effects of a low-fat vegan diet on body weight, found that people lost significant amounts of weight with no calorie counting.
On average, the low-fat vegan diet adopters lost 13 pounds in 14 weeks. This phenomenon can be partly explained by the thermic effects of eating plant-based foods. Vegan diets are higher in complex carbohydrates which cause the body to release some calories as body heat during digestion (the thermic effect) rather than store it as fat.
In fact a vegan diet includes a rich variety of foods that have a thermic effect (see list below). We sometimes get a thermic effect with animal protein, but we are also stuck with all the animal fat that comes with it.
A whole foods, plant-based diet causes you to burn calories 16 percent faster after meals for about three hours. This revving up of your metabolism causes gradual and healthy weight loss. The thermic effect alone does not cause the weight loss. What it does is help decrease the number of calories that are automatically converted into fat—stopping some fat before it starts.
It’s a natural process that is aided significantly by choosing a plant-based diet and hampered by a diet high in animal fats.
In this same vein, when you eat a plant-based diet you dramatically boost (by an average of 60 percent) activity of the enzyme carnitine palmitoyltransferase, responsible for shoveling the fat we eat into the furnaces (mitochondria) in our cells to be burned for energy. This may help explain why those eating vegan are so much slimmer. Another reason for the easy weight loss that comes with a plant-based diet is that fiber naturally calms the appetite: it leaves the stomach slowly, making us feel full longer, so we end up eating fewer calories overall.