I’ve been on-and-off low carbohydrate dieting for a few years now. My personal problem is lack of discipline. The trend goes like this: I realize I’ve put on more weight than I meant to, I get serious about eating better, I cut excess sugar, alcohol, and useless carbohydrates from my diet, I drop some weight, apathy sets in, I get bored following a rigid diet, repeat.
My rationale for following a low carbohydrate diet is quite simple, despite its multi-step formula:
- Eating triggers the pancreas to release insulin in varying amounts depending on the macronutrient (sugar=high, fat=low, protein=sustained medium).
- Insulin delivers the broken down components of food (glucose, fatty acids, etc) to our cells to use for energy and storage
- Excess eating triggers excess insulin
- Over time, muscle cells become resistant to insulin delivery, which leads to higher levels of insulin in the blood, along with higher levels of glucose in the blood. This eventually leads to metabolic syndrome, and for many, type 2 diabetes
- High levels of insulin causes muscle cells to prioritize glucose uptake, rather than fat metabolism.
- High insulin encourages free fatty acids to be stored in fat cells.
- High insulin discourages stored fatty acids (triglycerides) from being broken down and released from fat cells
- This creates an environment where stored fat tends not to be used for energy, which leads to fat accumulation
- Limiting the initial secretion of insulin prevents this fat accumulation in fat cells
- This can be done by caloric restriction
- Theoretically, it could also be done by eating foods that are less insulinogenic (insulin secreting)
Over the past few months, I have become receptive to the idea of time-restricted feeding (also sometimes referred to as intermittent fasting). One problem overweight people can face is that their base insulin levels tend to be higher than non-overweight people. It can literally be the case that an overweight person’s fasting insulin level is higher than a thin person’s post-eating insulin level!
*Source: Twenty-Four-Hour Profiles and Pulsatile Patterns of Insulin Secretion in Normal and Obese Subjects; Polonsky, Given, and Cauter
One strategy I recently tried was to use time restricted feeding (a daily routine of going 16-20 hours without eating – eating within a 4-8 hour window) without limiting carbohydrates. This did not work very well, and I found myself stagnating in weight loss while I was doing it. When I combined low carbohydrate eating with intermittent fasting, weight loss resumed. One thing I do not know is whether my caloric intake was high when I did this (I suspect it was).
As I mentioned above, I tend to lose momentum in my weight loss efforts, and then gain the weight back. So, I thought I would add some extra incentive for myself by adding an extra layer of intrigue to the process.
One of the things I have wondered for a long time is how caloric intake relates to this weight loss process, versus macronutrient composition. For example, if I eat 2500 calories comprised mostly of fat (say, at least 65% fat), will that affect weight loss (or gain) differently than if those 2500 calories came mostly from carbohydrates?
Different camps of researchers have different opinions about this, but the majority of researchers (at least from what I can tell) advocate a calories-in-calories-out model, rather than assuming the above insulin model implies one can increase their fat proportion of their diet to lose wight.
My gut instinct, based on research from Kevin Hall (source 1), is that the differences in weight change will be negligible, regardless of macronutrient composition (given consistent caloric intake/deficit) – one article Hall authored even suggested fat restriction is more effective than carbohydrate restriction; I suspect the reason low carb diets tend to be more successful than other diets has to do with satiety – high fat diets lead people to be less hungry. It also seems to be the case that it is much easier to overeat high carbohydrate food than it is to eat high fat food. However, Hall has also stated that protein metabolism is different enough from carbohydrate and fat that people can eat more protein calories than the other macronutrients.
I have to admit, I am drawn to the idea that we can alter macronutrient composition and be able to eat more than we otherwise would in a high carbohydrate diet.
My plan is to build statistical models to answer the following questions:
- Is caloric intake predictive of daily weight change?
- Does macronutrient composition data improve the models I create?
- Is macronutrient composition a better predictor of weight change than caloric intake? (especially when caloric intake is high)
- Is there anything surprising from the (to-be-created) models?
This process will require tedious calorie counting, food weighing, and abstinence from eating foods that I don’t know enough about. I’ve been collecting data for 5 days, and the data I have is shown below. Once I have more data, I can begin building statistical models. The trouble is my current data tells me very little right now, as my low carb+time restricted feeding has led me to lose weight every day so far. Clearly my basal metabolic rate is more than 1800-2000 calories per day…at least when time restricting and limiting carbohydrates.
My goal is to collect many different days with varying caloric intake, time restricted feeding, and macronutrient composition. As the dataset grows, the model will be more reliable…at least for my own body chemistry.