Commercial Diet Programs: Overview
Last updated: 20 February 2026
Commercial diet programs are paid weight-loss or diet services offered by companies. Well-known examples include the Weight Watchers diet (WW), Noom diet, Optavia diet, Cambridge diet, Medifast diet, SlimFast diet (or slim fast diet), GOLO diet, the 1:1 diet (also called one to one diet), Diet-to-Go, and the HMR diet. They can provide structure, support, or convenience, but they are not the only way to lose weight–a calorie deficit from ordinary food can also work. This page gives an overview of what commercial diet programs are, how they typically work, what to consider, and how they compare in broad categories. We do not endorse or recommend any specific program. Always discuss any diet change with your doctor or dietitian.
Disclaimer: This page is for education only. DietaBest does not recommend or endorse any commercial diet program. Before starting any diet, especially commercial programs that use very low calories or meal replacements, speak to your doctor. Results and safety depend on your health and how you follow the program.
Below you will find a definition of commercial diet programs, how programs like the Weight Watchers diet, Noom diet, Optavia diet, Cambridge diet, Medifast diet, SlimFast diet, GOLO diet, 1:1 diet / one to one diet, Diet-to-Go, and HMR diet generally work, a simple table of types, benefits and risks to consider, and answers to common questions. You can use our calorie calculator and TDEE calculator whether or not you use a commercial program.
What are commercial diet programs?
Commercial diet programs are for-profit services that help people lose weight or change how they eat. They usually charge a fee (subscription, products, or both) and may offer apps, meetings, coaching, meal replacements, or prepared meals. Examples people often search for include the Weight Watchers diet (WW, points-based), the Noom diet (app and psychology-based), the Optavia diet (branded “fuelings” and lean-and-green meals), the Cambridge diet (meal replacements, various plans), the Medifast diet (meal replacements and one “lean and green” meal), the SlimFast diet or slim fast diet (shakes and meal replacements), the GOLO diet (release supplement and meal plan), the 1:1 diet or one to one diet (consultant-led, meal replacements), Diet-to-Go (prepared meals delivered), and the HMR diet (Health Management Resources–shakes, meals, and/or classes). There is no single “commercial diet”; each program has its own rules, products, and cost. We do not recommend one over another.
Core idea
Most commercial diet programs aim to create a calorie deficit so you lose weight. They do this by controlling portions, points, or calories (e.g. through meal replacements or prepared meals) and often add support (app, coach, or group). Long-term success usually depends on what you eat and do after the program ends.
How commercial diet programs typically work
Programs fall into rough categories. The Weight Watchers diet uses a points system and optional in-person or digital meetings. The Noom diet uses an app with daily tasks, food logging, and lessons on behaviour and psychology. The Optavia diet and Medifast diet use branded meal replacements (e.g. bars, shakes) plus one or two “lean and green” meals you prepare. The Cambridge diet uses its own meal replacement products in steps from very low calorie to more food. The SlimFast diet (slim fast diet) relies on shakes and snack bars with one or two regular meals. The GOLO diet combines a supplement (“Release”) with a meal plan. The 1:1 diet (one to one diet) is consultant-led and uses meal replacement products. Diet-to-Go and the HMR diet offer prepared meals (and HMR also shakes and in-person/phone support). All of these are designed to simplify eating and reduce calories; some are very low in calories and should only be used with medical guidance. Use our TDEE calculator to understand your calorie needs regardless of which program you consider.
Types of commercial diet programs (overview)
This table groups programmes by general approach. We do not endorse any of them.
| Type | Examples (for information only) | Typical approach |
|---|---|---|
| Points / app / behaviour | Weight Watchers diet (WW), Noom diet | Points or calories in app; optional coaching or lessons |
| Meal replacements + meals | Optavia diet, Medifast diet, Cambridge diet, SlimFast diet, 1:1 diet (one to one diet) | Branded shakes/bars + one or more “real” meals; some plans very low calorie |
| Supplement + plan | GOLO diet | Release supplement + structured meal plan |
| Prepared meals / delivery | Diet-to-Go, HMR diet | Meals (and sometimes shakes) delivered; may include support |
Programs change over time (products, names, plans). Always check the provider’s current offer and talk to your doctor before starting, especially the Cambridge diet, Optavia diet, or Medifast diet if you are on a very low calorie plan.
Potential benefits of using a commercial program
Benefits depend on the program and the person. We do not recommend any specific one.
- Structure: Points, meal replacements, or prepared meals can make it easier to control calories without counting every gram.
- Support: Apps, coaches, or groups (e.g. Weight Watchers diet, Noom diet) may help some people stay on track.
- Convenience: Programs like Diet-to-Go or HMR diet reduce cooking and planning.
Weight loss on any program still comes from a calorie deficit. You can also create that deficit with normal food–see our weight loss diet and calorie deficit calculator.
Risks and what to consider
Commercial diet programs are not risk-free and are not right for everyone.
- Very low calorie plans: The Cambridge diet, some Optavia diet or Medifast diet plans, and similar programmes can be very low in calories. They may cause fatigue, nutrient gaps, or other problems and are not suitable for children, pregnant women, or many people with medical conditions. Use only with medical approval.
- Cost: Subscriptions and products can be expensive. Check total cost and whether you can sustain the approach long term.
- After the program: When you stop meal replacements or points, weight can return unless you adopt a sustainable way of eating. A dietitian can help you plan the transition.
- Supplements: Programs that include supplements (e.g. GOLO diet) should be discussed with your doctor, especially if you take other medicines.
Before joining any commercial diet program, talk to your doctor. If you have diabetes, heart disease, or other conditions, get clear guidance on which programmes are safe for you.
What to look for when considering a program
There is no “sample day” for commercial programs here because each one is different. When you look at options like the Weight Watchers diet, Noom diet, Optavia diet, Cambridge diet, Medifast diet, SlimFast diet, GOLO diet, 1:1 diet / one to one diet, Diet-to-Go, or HMR diet, consider:
- Whether your doctor agrees it is safe for you (especially for very low calorie or meal-replacement plans).
- Total cost and whether you can afford it for as long as you need.
- Whether the program teaches you how to eat after you stop (maintenance).
- Whether you prefer app-only, in-person support, or delivered meals.
You can also lose weight without a commercial program by using our calorie calculator, TDEE calculator, and calorie deficit calculator and working with a dietitian. See our weight loss diet and calorie deficit diet guides for a non-commercial approach.
Frequently asked questions
Commercial diet programs are paid weight-loss or diet services offered by companies. Examples include the Weight Watchers diet (WW), Noom diet, Optavia diet, Cambridge diet, Medifast diet, SlimFast diet, GOLO diet, the 1:1 diet (one to one diet), Diet-to-Go, and HMR diet. They may use points, apps, meal replacements, prepared meals, or coaching.
They work in different ways: some use a points system (e.g. Weight Watchers diet), some use an app and psychology (e.g. Noom diet), some use meal replacements or fuelings (e.g. Optavia diet, Medifast diet, Cambridge diet, SlimFast diet), and some deliver prepared meals (e.g. Diet-to-Go, HMR diet). Most aim to create a calorie deficit for weight loss.
Safety depends on the program and your health. Very low-calorie or meal-replacement programmes (e.g. some Cambridge diet or Optavia diet plans) may not be suitable for everyone. Always check with your doctor before starting any commercial diet program, especially if you have medical conditions or take medication.
No. DietaBest does not endorse or recommend any specific commercial diet program. This page is for education only. You can also lose weight with a calorie deficit from regular food–see our weight loss diet and calorie deficit calculators.
The Weight Watchers diet (WW) uses a points system and optional meetings. The Noom diet is app-based and focuses on behaviour and psychology. The Optavia diet uses branded meal replacements (fuelings) plus one lean-and-green meal. Each has different cost, structure, and food approach. We do not recommend one over another.
Consider cost, sustainability after the program ends, whether you need medical supervision (e.g. for very low calorie plans), and whether the program fits your lifestyle. Talk to your doctor. You can also achieve weight loss with a calorie deficit using our calorie and TDEE calculators and a dietitian.
Summary
Commercial diet programs are paid services that help people lose weight through structure, support, or convenience. Examples include the Weight Watchers diet, Noom diet, Optavia diet, Cambridge diet, Medifast diet, SlimFast diet (slim fast diet), GOLO diet, 1:1 diet (one to one diet), Diet-to-Go, and HMR diet. They work in different ways (points, apps, meal replacements, prepared meals). We do not endorse or recommend any of them. Very low calorie programmes need medical approval. Before starting any program, talk to your doctor or dietitian. You can also lose weight with a calorie deficit from normal food–use our calorie calculator, TDEE calculator, and calorie deficit calculator and see our weight loss diet and calorie deficit diet guides.
Use our calculators with this diet
Set your calorie target and plan meals with our free tools.
You might also like
Other diet guides that may fit your goals.
Weight loss diet
Balanced eating with a calorie deficit for sustainable weight loss.
Calorie deficit & low-calorie diet
Eating below maintenance calories for weight loss.
Mediterranean diet
Plant-forward eating with olive oil, fish and vegetables. Often recommended for heart health.
Low-carb diet
Fewer carbs, more protein and fat. Used for weight loss and blood sugar.
Sources and further reading
This article is for general education. Program details (pricing, plans, products) change; check each provider’s official site. For evidence on weight loss and commercial programmes, see:
- Systematic reviews comparing commercial weight-loss programmes (e.g. Weight Watchers, meal replacements) with standard care or self-help
- Guidance from national health bodies on very low calorie diets and when they require medical supervision
Last updated: 20 February 2026. Content is for educational purposes only and does not replace medical advice. We do not endorse any commercial diet program.