I’m not impressed by vegan athletes. All those breathless headlines about how this or that highly successful athlete does all this on a plant based diet. Guess what? Those guys and gals eat so much they can’t help but meet all their nutritional requirements. They don’t have to think about it.

You know what’s hard? Thriving on 1200 calories per day.

In one of the Facebook groups I belong to, a woman in her fifties was extolling the virtues of her mostly raw vegan diet compared to her more conventional wfpb diet by explaining that her body fat percentage had dropped from 18% to 15%. By any standard, this woman was skinny before and skinnier now.

There are certain figures in the wfpb world who advocate maintaining one’s weight in the very lowest ranges of “normal”. They typically promote a diet which by its nature is very low in calories. The Eat to Live program, for example, prescribes eating a pound each of cooked and raw vegetables per day and only 1 serving of whole grains. I found a typical daily menu that follows the ETL guidelines and entered it into Cronometer. It provides a whopping 1350 calories per day. That is barely enough energy to spend your day in a coma, let alone to actually live your life.

Happy Herbivore offers a 1200 calorie a day meal plan and Chef AJ is another of the very low calorie diet advocates. Anyone who is promoting a raw diet, unless they eat a lot of coconut oil and avocado is also offering very few calories.

I poked around the web a bit while researching this, and I noticed that there seems to be a pattern to the blogs of people who follow these plans. They discover one of these programs, follow it, lose weight, go offline for a few months, come back with a story of a life event that derailed their efforts and caused weight gain, restart the diet or another similar one, lose weight, repeat.

I admire the tenacity of anyone who can keep that cycle up for years, but here’s what I think: if you want to be a weight that requires a severely calorie restricted diet to maintain, you may want to reconsider your goals. There are a couple of reasons for this.

First, your body is no fool. You can fill up your stomach all you want with low calorie vegetables, but if you aren’t meeting your energy and nutrient needs, you are going to be hungry. Hunger is a state that quite rightly demands all of your attention. You may be able to manage for a while, but sooner or later, your attention will slip and you will lose the battle with your body.

Second, a calorie restricted diet is not just lower in energy, but in other nutrients as well. I think this is really important. We see articles all the time about how even athletes can thrive on a vegan diet. Here’s the thing. An athlete can easily require 3000 to 5000 calories per day. If an athlete requires twice as much energy as an ordinary person, and meets those requirements on a healthy vegan diet, then they are also getting twice as much of every other nutrient as well. Of course they can thrive! If I’m a skinny minnie and consume half as many calories as an ordinary person, then I will get half as many of the other nutrients as well. My Cronometer exercise with the ETL diet showed a deficiency in several amino acids (yes, it is possible to have a protein deficiency), iron, calcium, some B vitamins and some minerals.

The promise of these vegan weight loss programs is that they are highly nutritious due to their extraordinary vegetable content. They are far more nutritious than the Standard American Diet, which contains very few whole fruits and vegetables, but that advantage is much diminished against a complete whole foods diet including fruits, vegetables, whole grains, legumes, nuts and seeds. The other promise is that you need never count calories. Which is not to say that calories aren’t important, just that you don’t need to count them if you are following the rules, because the rules ensure you eat a very low calorie diet.

If you are overweight or obese and just starting out on a wfpb diet and you have been consuming an ordinary western diet up until now, I have no doubt you will lose weight. Even if you are not following one of the specific weight loss programs. If you are looking for specific advice about what to eat in a day, I highly recommend Dr. Greger’s Daily Dozen. These are guidelines for minimum quantities of different categories of foods described in his book How Not To Die. There is an app that provides an easy way to keep track of them.

I am less certain that you will be able to start a bikini modelling career, or that you will ever fit into a size 2. Depending on your body type and your history, it may require serious body hacking to get that small. But those hacks may not actually be compatible with the best health outcome.

Bone health, in particular, can be compromised on a very low calorie diet.

I went from a size 14-16 to size 8-10. My bmi is in the normal range, but by Hollywood standards I’m huge. Compared to most people my age I’m actually kind of small. Along with pretty much every other woman I know, I feel some pressure to keep working on my body until it conforms to the current standards of perfection. Luckily my desire to not be hungry is way more powerful than my desire to be skinny.

Here’s what will always be good for you. Eat a complete whole foods, plant-based diet along the lines of Dr. Greger’s Daily Dozen. Get daily aerobic exercise. Do strength exercises at least a couple of times per week. Don’t let yourself be hungry. Don’t fear complex carbs (the ones found in starchy vegetables and whole grains and legumes). Don’t fear fruit. Don’t worry if you aren’t a size 2.

And don’t take nutrition advice from anyone who eats less than 1400 or more than 4000 calories per day.