101: How Lipoprotein Lipase (LPL) Determines Where Your Body Stores Fat with Dr. Ben Bikman

Bikman frames insulin as the most powerful controller of LPL. He explains that even a low-fat, high-carb meal elevates insulin, which promotes liver VLDL synthesis and adipose LPL activation, turning carbohydrates into stored fat. By restricting carbs, insulin remains low, so adipose LPL activity declines and muscle LPL is uninhibited. A 2009 study in AJP Endo confirmed that low-carb diets significantly increase muscle LPL compared to high-carb diets; the adipose effect is more modest but still in the desired direction. He emphasizes that you are ‘storing less, burning more.’ He also cautions that some animal studies have shown contradictory results, so human data should be prioritized. The protocol is presented as the foundational dietary change for anyone wanting to influence fat storage through LPL modulation.

Bikman points to early studies (1978, 1979) demonstrating that endurance-trained individuals have elevated muscle LPL activity, correlated with lower blood triglycerides and higher muscle fat oxidation. Prolonged exercise decreases adipose LPL activity while increasing it in muscle, changes mediated largely by adrenaline. He explains that adrenaline also signals the pancreas to lower insulin, further removing the brake on muscle LPL. The overall effect is to shift the body into a fat-burning mode. He notes that the regulation is post-translational—quick and responsive. While much of the research is on endurance exercise, the principle extends to any activity that produces sustained catecholamine release.

Bikman describes the weight-loss LPL paradox: despite lower activity, the genetic machinery ramps up, readying fat cells for storage. He references a 1999 study where very-low-calorie diet reduced activity but not expression, and Jim Hill’s group’s 2012 paper that highlighted the predictive value of post-weight-loss LPL responsiveness to carbs. Bikman suggests that staying on a low-carb diet during maintenance could blunt this LPL-mediated regain, though he acknowledges the absence of a head-to-head trial. This segment provides a compelling argument for why many people regain weight and how LPL is a central culprit, recommending carbohydrate vigilance as a practical countermeasure.

Bikman dedicates a section to thyroid hormone, noting T3’s ability to boost LPL expression while also revving up mitochondrial fat burning, making the net effect often fat loss despite increased enzyme production. He stresses that hypothyroidism dampens LPL activity, particularly in muscle, contributing to weight gain. Therefore, proper thyroid management is crucial for those with a deficiency. However, he reiterates that insulin remains the master regulator; even with optimal T3, high insulin can override LPL’s fat-burning signals. This protocol is not a stand-alone weight-loss strategy but a necessary correction for an underlying endocrine issue.

Dr. Bikman explains that LPL sits on the endothelial cells lining blood vessels, especially in capillaries of adipose tissue, skeletal muscle, heart, and lactating mammary glands. It grabs triglyceride-rich lipoproteins (chylomicrons from the gut after a meal, VLDL from the liver) and clips off fatty acids. In adipose those fatty acids are re-esterified into triglycerides for storage; in muscle they are oxidized for energy. This enzymatic step decides whether a fat molecule is stashed or burned. The enzyme is a ‘multitasking maestro’—it also helps clear cholesterol-rich remnants and fat-soluble vitamins. Throughout the lecture, Bikman weaves in how insulin, sex hormones, thyroid, diet, and exercise all act by tweaking LPL activity, not just general metabolism. This enzyme is the final common pathway for fat partitioning.

After a mixed meal, insulin spikes. In adipose tissue, insulin enhances LPL activity by promoting the enzyme’s movement to capillary walls, increasing triglyceride breakdown and fatty acid uptake for re-esterification and storage. At the same time, insulin suppresses LPL in muscle, reducing fatty acid uptake and oxidation. This dual action ensures that when calories are plentiful, fat is stored rather than burned. Bikman cites a 1987 Metabolism paper showing post-translational regulation: insulin doesn’t change how much LPL is made, but how functionally active it is. Moreover, insulin promotes VLDL production in the liver, converting excess glucose into triglycerides that are then distributed. Thus, a high-carb, low-fat diet still leads to fat accumulation because insulin orchestrates the entire system—from VLDL creation to adipose LPL activation. Bikman states bluntly that ‘none of them matter like insulin does’ when comparing other hormones.

When insulin is low—as on a diet of ~50 g carbs per day—adipose LPL activity declines, so fewer fatty acids are pulled from circulating VLDL and chylomicrons into fat cells. Meanwhile, the brake on muscle LPL is released, allowing muscle to increase fatty acid uptake for beta-oxidation. Bikman notes that the effect in muscle is particularly robust: a 2009 study in AJ Pendo found low-carb diets significantly increased muscle LPL compared to high-carb diets, while the adipose effect was less dramatic. This asymmetry still yields a net metabolic benefit—‘you're storing less, you're burning more.’ He also cautions about animal studies showing different results, emphasizing human data. The takeaway: controlling carbs to control insulin is the most direct way to manipulate LPL to reduce fat storage and enhance fat burning.

Bikman references a 1999 Journal of Endocrinological Investigation study showing that a very low-calorie diet reduced adipose LPL activity but did not lower expression—in fact, gene expression often rose, particularly in those who had been obese. He likens it to the body ‘priming itself to store fat again if the situation gets favorable.’ This concept is reinforced by work from Jim Hill’s group at Colorado: a 2012 Obesity study found that individuals who had a high adipose LPL response to a high-carb meal after weight loss were significantly more likely to regain fat over four years. Bikman suggests that this LPL-mediated rebound could be mitigated by keeping carbs low during maintenance, though he laments that no trial has directly tested a post-weight-loss low-carb vs. high-carb diet on LPL outcomes. The segment offers both a mechanistic explanation for the common yo-yo pattern and a possible solution.

Bikman explains that during adolescence, sex hormones direct LPL expression and activity. In girls, estrogens upregulate LPL specifically in subcutaneous fat of the breasts, buttocks, and hips—areas associated with a female body shape. This promotes fat storage in a way that actually improves insulin sensitivity. In boys, rising testosterone suppresses subcutaneous LPL, reducing overall fat storage but increasing the potential for visceral fat accumulation, which is linked to insulin resistance. He cites a 1990 JCEM study that found higher LPL activity in female gluteal (buttock) fat driven by estrogen. These tissue-specific patterns set the stage for lifelong metabolic differences between men and women, with women’s subcutaneous fat serving as a protective metabolic sink so long as it doesn’t become overwhelmed.

Bikman describes T3 (triiodothyronine) as a significant regulator of LPL. In adipose tissue, T3 boosts LPL expression, increasing the enzyme’s production and enhancing triglyceride breakdown for fatty acid uptake. However, T3 also ramps up mitochondrial function, which can accelerate fat burning within those same cells. In skeletal muscle, T3 increases LPL activity, directing fatty acids toward oxidation for energy. Consequently, someone with hyperthyroidism may have high LPL but also high burning, leading to fat loss. In hypothyroidism, low T3 reduces LPL activity, particularly in muscle, impairing fat oxidation and contributing to fat gain. Bikman emphasizes that while thyroid hormone matters, it is subordinate to insulin: ‘any of the other signals I mentioned don't matter in the absence of insulin.’ This hierarchy is critical when interpreting endocrine disorders.