Although I’ve written extensively on the human microbiome, inflammation and weight loss before, I’ve yet to compile a simple list that will help you lose weight in a healthy manner. Research has made it clear that just looking at calories in vs. calories out is a simplistic view on overweight and obesity. Of course you have to expend more calories than you take in if you want to lose weight, but we now know that several factors such as macronutrient ratio, genetics, inflammation and microbes strongly influence if we gain or lose weight.
A short summary of the science
NB! Since this is going to be a simple guide on how to lose weight I’m not going to spend a lot of time discussing the scientific research on overweight and obesity. Rather I’m going to summarize some of the literature on overweight and obesity that is relevant to this post.
- You have to expend more calories than you consume in order to lose weight
This does not mean that just reducing the amount of calories you take in is the optimal strategy to lose weight. Different types of food affect your body in different ways (e.g, hormones, gut health, metabolism), and the composition of your diet influences how much energy you eat, burn, and store.
- Obese individuals have an altered microbiome (1,2)
Research on the human microbiome has made it clear that lean and obese individuals harbor different microroganisms.
- Obesity is characterized by low-level chronic inflammation (3,4)
Inflammation is an important underlying cause of leptin resistance and insulin resistance, two conditions that will make it harder to lose or maintain bodyweight. Whether this inflammation preceds or contributes to the weight gain isn’t fully established. Fat tissue can in itself be proinflammatory, and the visceral fat around the organs is especially unhealthy. The fact that high serum LPS activity is strongly associated with the components of the metabolic syndrome suggests that poor diets, dysbiosis and increased intestinal permeability are major causes of inflammation in obese and overweight individuals.
- Antinutrients in neolithic foods could negatively impact health (5,6,7,8,9)
Antinutrients (e.g., gluten, lectins) commonly found in grains and legumes MIGHT promote leaky gut and inflammation, but some data show that a healthy microbiome can protect against the harmful effects of secondary metabolites. Individuals with gut dysbiosis and leaky gut usually benefit from excluding most grains from their diet.
- Reducing carbohydrate intake is often beneficial (10,11,12,13,14)
Clinical trials show that LCD (Low-carbohydrate diets ≈ 5-20% energy from cabrohydrate) usually promote superior results in regards to weight loss compared to HCD (high-carbohydrate diets ≈ 45-60% energy from carbohydrate). Subjects on a LCD usually consume fewer calories than subjects on a HCD even when both groups are allowed to eat as much as they want (ad libitum). Nutrient density, hormonal response, inflammatory response, effect on microbiota etc. probably explain the beneficial effect of lowering the carbohydrate content of the diet. While it seems that reducing the overall carbohydrate content of the diet is linked to increased weight loss, it’s possible that acelluar and refined carbohydrates are the major offenders on a high-carbohydrate diet that promote an inflammatory microbiota, chronic low-level inflammation, and weight gain.
- Ancestral/paleolithic diets often show favorable results in regards to weight loss and health (15,16,17,18)
The available data unanimously show that hunter-gatherer societies are virtually free from non-communicable chronic disease. Although several other aspects (e.g., sun exposure, time outdoors, microbes) besides diet have an impact on health, it’s safe to assume that the consumption of mostly paleolithic whole foods in these societies is very beneficial to their health. Clinical trials also show that the paleo diet promotes weight loss and improves markers of health. Eating a nutrient-dense ancestral diet usually results in greater satiety, lower energy intake (without counting), and weight loss.
- Food reward plays an important role in overweight and obesity (18,19,20,21,22,23)
It seems that that comsumption of modern hyper-palatable and hyper-rewarding food (e.g., processed calorie-dense foods rich in fat and/or sugar) disrupts the brain’s mechanisms for regulating food intake. “…the increased palatability of the diet initiates a vicious cycle in which hedonics cause more food to be eaten than is necessary to meet energy needs, and the increased calories in turn initiate events that lead to insulin/leptin resistance and a consequent tendency to eat even more food” (18).
- Exercise could speed up weight loss
– Compensatory mechanisms (e..g, hunger and increased energy consumption) to exercise often make the trainee compensate for the exercise-induced energy expenditure.
– Exercise can reduce inflammation and improve leptin and insulin sensitivity, which in turn help promote weight loss
– Some people lose a lot of weight by just exercising more (responders), while others actually gain weight due to compensatory mechanisms (non-responders)
– Both anaerobic (without oxygen) and aerobic activity (with oxygen) can speed up weight loss, but diet is more important
- Both studies in animals and humans show that the appetite for protein is so strong that you will keep eating until you get enough protein. Lack of protein in the diet could lead to overeating (24,25).
4 things to do for weight loss
- Eat primarily nutrient-rich whole foods
Eat mostly meat, seafood, fowl, eggs, berries, vegetables, nuts (in moderation), fruits (in moderation), and whole-fat dairy (in moderation). Try to get as much organic and grass-fed produce as possible. Some traditionally prepared grains and legumes can be a part of your diet if you tolerate them well. Sticking to an ancestral food template results in a lower carbohydrate intake than the typical western diet unless you indulge in fruits and starchy tubers. Animal source foods seem to be especially important for someone who wants to lose weight, as lack of protein in the diet can lead to overeating. A diet based on unrefined traditional foods should make you lose weight even without counting calories and starving yourself. Don’t obsess over the diet, but try to stick with it for 80-90% of the time.
- Eat high-quality fermented foods
Avoid the acidophilus milk at the supermarket, and try instead to find quality products such as Kimchi and Kefir at the health food store, farmer’s market or some other trusted source. Fermented foods can also be made at home.
- Eat plenty of vegetables
Soluble fiber and resistant starch are two of the components in fruits, vegetables and other plants that work as prebiotics in the gastrointestinal tract. Leeks, onions and jerusalem artichoke are especially rich in soluble fibers such as inulin. Prebiotics are the food source of the bacteria, and several sources of prebiotics in the diet usually improve the bacterial composition in the gut.
Regularly perform some type of aerobic and anaerobic exercise. The frequency, duration and intensity of the exercise depends on your goals. If the primary goal is to lose weight, 1-2 days of resistance training with bodyweight and barbell exercises, and 1-2 days of walking, running, rowing etc. could be a good start.
Other factors that could help speed up weight loss include getting adequate sun exposure, taking a high-quality probiotic supplement, increasing omega-3 intake and getting more microbes into your life (e..g, eating plants from the farmer’s market or garden, avoiding excessive hygiene).