3 ways to figure out what a new diet would cost you

Flickr / ImpromptuKitchen

Two months ago, Joshua Schall, a business consultant in Austin, Texas, decided to try the ketogenic diet, keto for short, which forces the body to burn fat instead of carbohydrates.

Schall, who used to be a fitness writer, was curious about the hype and thought he'd give it a shot. The diet, it should be noted, hasn't won over the medical profession for weight loss among the general public (though it's used medically to control epilepsy).

In any case, Schall lost nine pounds, but he also got rid of some bloat in his budget.

"I lowered my grocery bill 20 percent to about $75 a week," Schall says. "The main difference was being able to buy cheaper cuts of meat from my traditional lean cuts." He also cut down on purchasing flavored drinks and juices.

Americans spend billions of dollars a year in an effort to lose weight, but it's easy to forget that occasionally, consumers save money in their quest. Eating less food, after all, should translate into more cash.

Still, consumers probably spend more than they save. According to a recent IBISWorld report, companies that help people lose weight, like Weight Watchers and Nutrisystem, made $6.3 billion in 2015. And that doesn't include the billions that Americans also spend on dietary supplements, gym memberships, diet books and weight-loss surgery.

So how much will you save or lose if you start dieting? There's no way to say, since everyone eats, shops and lives their lives differently. But if you're going to go on a diet, you might want to think about how the change in your eating habits will affect your finances. Here, we examine three scenarios.

1. You could join a weight-loss program.

The pros: You'll hopefully learn how to eat better, and in some cases, you'll be given meal plans complete with packaged meals and snacks that will help you lose weight.

Bonus: Meal plans can take the stress out of designing a menu and may largely eliminate grocery shopping (at least for yourself; if you have a family to feed, then it's another story). The cons: These weight-loss programs are rarely cheap.

You might still save money in the long run if your grocery bill shrinks, and, of course, if you get the healthy results you're looking for, you may not mind spending the money.

If you give a weight-loss program a try, remember that you'll likely face a membership fee and possibly the cost of a customized meal plan and food. To give you a sense of what you might pay, here are cost breakdowns for a handful of programs.

Weight Watchers. According to its website, the cost varies, depending where you live, although after plugging in ZIP codes for several cities – Cincinnati, New York, San Francisco, Dallas and Omaha – the same prices kept popping up. For those areas of the country at least, you might pay, at minimum, $3.07 a week to join the online program and $6.92 a week if you want the online program in addition to the ability to attend support meetings (this presumes that you purchase a three-month plan). Throw in personal weight-loss coaching, and you'll pay at least $8.46 a week.

The standard monthly plan (which means not buying a three-month plan) to use the website and go to meetings is $44.95.

Jenny Craig. In this case, the bulk of your expense will come from ordering most of your food through Jenny Craig. If you follow the program, you'll be eating six times a day: three main meals and three snacks. There are two programs, All Access and As You Go. The food costs vary but typically range between $15 and $23 per day, plus shipping, according to the company. There is also a $19-a-month membership fee and the $99 enrollment fee, although sometimes the enrollment fee is discounted.

As for those shipping costs, you will likely get your food once or twice a month, and standard shipping costs range from $29 to $58 per order, depending how much food you're buying. If you go with express shipping, expect to pay more. But if there's a Jenny Craig center nearby, you can eliminate those costs by picking up your food there.

You'll also still need to buy certain staples on your own like fruit, vegetables and milk.

Nutrisystem. Like Jenny Craig, you'll receive your food in the mail through FedEx. Prices range from around $9 to $11 a day, depending what you plan you go with, and the shipping costs are free (or more accurately, the shipping costs are added into the expense of the program, so you don't have to think about them).

There is no monthly membership fee or enrollment fee. There is a cancellation fee of $30, if you terminate after your order has shipped or the food is delivered but you refuse to take it.

BistroMD. Its claim to fame is that the packaged meals are designed by a doctor (that's where the MD in BistroMD comes in). It isn't cheap, but the cost includes free, unlimited support from registered dietitians. You can get a seven-day meal plan, a five-day plan or customize it to have fewer meals, like all lunches and dinners. The seven-day meal plan, for one month, is $674.81. The five-day meal plan, for one month, is $562.31.

2. You could go on a meat-free diet.

It isn't as if you have to join a weight-loss program to lose weight. You could, for instance, cut meat out of your diet, and see if you lose weight. Bonus: You probably will save money, according to Kelly Toups, the in-house dietitian for Oldways, a food and nutrition nonprofit educational organization based in Boston. Oldways has become well-known for promoting the Mediterranean diet.

"Current research backs up the notion that traditional plant-centered diets ... stand up nicely to modern food economics," says Toups, citing a 2015 study published in the Journal of Hunger & Environmental Nutrition, in which researchers calculated the cost of a seven-day meal plan using an economical version of USDA's MyPlate guidelines versus a plant-based diet with olive oil.

"They found that choosing a plant-based diet, instead of the budget MyPlate diet, could save $746.46 per person per year and provide vastly more servings of vegetables, fruits and whole grains," Toups says.

3. You could stop or slow down on eating out.

A few years ago, researchers at the University of Toronto analyzed menus at 19 sit-down restaurant chains. They found that the average meal contained 1,128 calories, which is quite a bit if you consider that the average daily calorie cap, according to the Food and Drug Administration, is 2,000. The same researchers found that the average fast-food meal has 881 calories. Bottom line? One meal out can cost you nearly half (or more) of your daily calorie allowance. 

If you really want to lose weight, and you're going to a lot of restaurants and fast-food joints, visit your friendly neighborhood supermarket instead and become reacquainted with your stove.

After all, it's hard to argue with the success Courtney Wilson has had. Wilson, a former army engineer captain and now a graduate student and entrepreneur in Newtown Highlands, Massachusetts, says that recently, she stopped eating out.

"I'd grab lunch at the school cafe and then takeout for dinner," Wilson says. Now, she cooks her meals.

"I lost 15 pounds in two months and saved $700 a month," Wilson says. "And I'm still losing."

Losing weight and gaining money? That may be the best diet ever.