I'm frequently asked these rabbit hole questions about weight loss: Which is better, the treadmill or the elliptical trainer? Should I use free weights or machines? Should I be following a low carb or low fat diet? Is it better to exercise first thing in the morning or later in the day? Is it better to eat 6 smaller meals than 3 main ones? To tell you the truth, when it comes to weight loss, these questions are extraneous and relatively unimportant. Spending time and energy on them is akin to rearranging chairs on the Titanic.
The scope of these questions is too narrow relative to the major principle that governs weight loss: calories spent must exceed calories eaten over the course of time. Every pound of fat you carry is equal to 3,500 calories of stored energy. If every day this week you spent 500 more calories than you took in, you would lose 1 pound (500 calories/day x 7 days/week = 3,500). Your output of calories includes the calories needed to maintain biologic functions at rest (called basal metabolic rate or BMR) plus any calories you spend in daily activity (walking to your car, vacuuming, etc.), work (desk job or landscaper), and, of course, exercise.
Bearing this cardinal principle in mind, can you see how those first questions become secondary? Take the treadmill versus elliptical inquiry, which is one that I hear very frequently: this debate is only important from the standpoint of interest (mixing up your workout helps keep you from getting bored) and also from the standpoint of injury prevention (the elliptical is low impact exercise). Does adding upper body motion as with the elliptical help you burn more calories? It's relative. Working hard on the treadmill beats going easy on the elliptical any day. If the work rates are about the same, which they are for most people, machine to machine, then the difference is negligible, especially in the larger picture.
An example of wasting time in a rabbit hole: someone wants to lose weight, but only exercises 2-3 times a week and frequently eats until they're overly full. This person wonders which piece of cardio will give them the most bang for their buck. Is there such a piece? Perhaps, but the difference between 30 minutes on that piece versus 30 minutes on another, is very small relative to other changes this person could make. Instead, this person should pan back and examine their frequency, intensity and time (F.I.T.) of both cardiovascular and strength training along with comparing their current diet to one that would be reduced-calorie, nutrient-dense and balanced. There's where this person should spend time and energy and, frankly, money. If this person started to exercise more frequently, more intensely and/or for a longer period of time, and started eating more moderately, then they would actually be doing something to elicit weight loss. On the other hand, if they continued with the same F.I.T. of exercise but changed from treadmill to elliptical, AND continued to eat the same way, would it matter toward weight loss? Absolutely not.
When it comes to really losing weight, don't waste time and energy rearranging chairs on the sinking ship. Recall the fundamental rule: calories in vs. calories out. Then apply F.I.T. principles, moderate your diet and get off the boat.
You can then visit the secondary layer principles that will address things like boredom and injury prevention.