A couple weeks ago I talking about how snacking may be related to obesity. If you look at the research on snacking, it is pretty unclear. It often shows benefits in some cases (like adolescents) and is linked to obesity in other studies. One issue that has received greater focus is that the overweight/obese may be underreporting food/snack intake and thus skewing the data.
In my opinion, snacking is not bad per se. If a person is hungry and they eat a snack, that's not a negative event. The problem is one a person becomes a "disassociated" eater – in other words, their eating is no longer governed by hunger and satiety.
In this situation, I think snacking can be a Pandora's box, because of the explosion of high-fat/high-sugar snacks and their constant availability. It would be like if a person is an alcoholic and there is a bar on every corner. The bar isn't forcing anyone to drink but its presence sure helps.
A study from a couple of years ago focused on this topic. The researchers found that the time between eating occassions had decreased over the past 30 years. For example, they found that the time between eating occassions has decreased by one hour compared to 30 years ago. So what could be causing this? Are people hungrier then they were 30 years ago?? I don't think so, especially given the fact that people are consuming more calories today.
I would say that this is a case of, again, eating in the absence of hunger. If hunger isn't driving food consumption, they a person may easily consume food more frequently because of snack availability.
Therefore, I would say that snacking is related to obesity but is not a true cause. Snacking when not hungry simply adds extra calories which can obviously lead to weight gain.
I am fairly convinced that snacking was what led me to put on extra weight after I went through “second puberty” – the hormonal shift that came in my mid-20s and caused, among other things, a reduced metabolism.
After being a consistent weight from about 18 to 25, I suddenly put on 15 lbs (making me 5 lbs overweight by BMI) with no change in diet or exercise, and could not get it off in more than a year of trying. Then I tried the Metabolic Balance nutrition program. It essentially combines a paleo-esque food list (no grains or sugar, limited fruit, heavy promotion of saturated fats and animal protein, but unlike paleo no restriction on cheese) with the requirement that each meal be eaten in an hour or less, and for five hours between meals you may only drink water. I was already on a gluten-free, minimal-grain, low-sugar diet, so the fasts between meals was the biggest change for me. I lost 25 lbs in 2 months following this plan and stabilized at a weight in the lower-middle of healthy BMI for my height.
I’ve since met others who had great success losing weight with a program called The Four Hour Body. From what I’ve read, it’s quite similar to Metabolic Balance in that it requires a four-hour water-only fast between each meal. These between-meal fasts allow your blood sugar and insulin levels to fall so that your body can burn from existing fat stores, while between-meal snacking elevates your blood sugar each time you consume more carbohydrate, triggering an insulin release which converts the blood sugar into body fat.