Skip to main content

The Globe and Mail

Does combining foods help with weight loss?

The question

Does food combining work? I've heard it's better for digestion and weight loss.

The answer

Story continues below advertisement

Food combining – restricting the types of foods that can be eaten together – has been the focus of many diet books over the years. The basic idea is that different food groups must be eaten at different times because the body digests different foods at different rates, using different enzymes.

Guiding principles of food combining diets are to avoid eating protein and carbohydrates (e.g. chicken and rice or pasta and meat sauce) together and to eat fruit alone on an empty stomach (usually in the morning). Advocates of this diet plan claim that improperly combining foods delays digestion, causing partially digested foods to ferment and rot in the stomach. They say this gut rot, in turn, leads to all sorts of problems including gas, bloating, low energy and weight gain.

The scientific rationale for food combing is flimsy at best. The human body has evolved to digest different types of foods at the same time. Digestion is a process that starts in the mouth and finishes in the intestinal tract. It's far too simplistic to say that protein requires certain enzymes for digestion and carbohydrates require others, and when combined they oppose each other so nothing gets properly digested. And there's no evidence that poorly combined foods ferment in your stomach.

There's also no data to show that the combination of foods eaten causes weight loss. In fact, one study published in 2000 in the International Journal of Obesity found no difference in pounds lost between dieters following a 1,000-calorie food-combining diet and a 1000-calorie balanced diet. Participants lost roughly seven kilograms, regardless of which diet they followed.

Most experts contend weight loss is due to eating fewer calories rather than the meticulous combining of foods. Makes sense if you consider you save 216 calories if you don't eat the brown rice (one cup) with your chicken and vegetable stir-fry and 185 calories if you forgo the ground beef (three ounces) in your spaghetti meal. And certainly a morning meal consisting only of fruit is much lighter than many other breakfasts.

Eating carbs with protein – or fruit with a meal – is just fine. Your body is perfectly capable of digesting and extracting the nutrients from these foods when eaten together. What's more, foods such as beans, lentils, nuts and seeds are blends of protein, carbohydrate and fat. In fact, most foods are made up of varying combinations of these three basic macronutrients.

In my opinion, it's often beneficial to combine foods at meals. Including protein with starch in a meal slows digestion and helps keep you feeling satisfied longer – something that can help, not hinder, weight loss efforts. Doing so also slows the release of sugar (glucose) into the bloodstream, stabilizing blood glucose levels for longer lasting energy.

Story continues below advertisement

The key – as always – is to manage your portion size. Eating too much protein, starch or fruit at a meal can cause you to feel bloated and lethargic and, over time, can add inches to your waistline. But this has nothing to do with food rotting in your gut.

Leslie Beck, a registered dietitian, is the national director of nutrition at BodyScience Medical. She can be seen every Thursday at noon on CTV News Channel'sDirect (

Click here to submit your questions. Our Health Experts will answer select questions, which could appear in The Globe and Mail and/or on The Globe and Mail web site. Your name will not be published if your question is chosen.

The content provided in The Globe and Mail's Ask a Health Expert centre is for information purposes only and is neither intended to be relied upon nor to be a substitute for professional medical advice, diagnosis or treatment.

Report an error

The Globe invites you to share your views. Please stay on topic and be respectful to everyone. For more information on our commenting policies and how our community-based moderation works, please read our Community Guidelines and our Terms and Conditions.

We’ve made some technical updates to our commenting software. If you are experiencing any issues posting comments, simply log out and log back in.

Discussion loading… ✨