Is Sugar the Problem?
By Meghna Motwani, Ph.D. & Avanti Maluste
We’ve seen it happen in the wild, and perhaps also done it ourselves: avoided sugar. Eliminated it from morning coffee, banished that afternoon cookie or the occasional dessert on a night out. And then (maybe) the pounds shed. It must be the sugar.
But is it?
Not exactly. In fact, we’d argue, based on the preponderance of research, likely not at all (1, 3). “Sugar” has a wide range of definitions: as glucose (that ubiquitous molecule that makes life possible), fructose (found in fruit), lactose (milk sugar, a combination of glucose and galactose) and cane sugar or sucrose (fructose and glucose). However, in this context, we narrow the definition slightly to sweetening agents such as sucrose (50% fructose, 50% glucose), high-fructose corn syrup (55% fructose, 50% glucose) or sugars present in sweetening agents such as jaggery, honey or maple syrup, each of which contain both fructose and glucose. It’s important to mention here that these “natural” sweeteners contain beneficial anti-oxidants, but likely at doses too low to be physiologically relevant when they are used as sweetening agents. The most important property for ingredients such as honey (other than its taste), is the amount of calories it contains.
So, what’s going on?
First, it’s important to establish the mechanisms by which weight (i.e. either fat or lean mass) is gained or lost. Biology is underwritten by thermodynamics, and weight fluctuations are a manifestation of that. A calorie surplus (consuming more than one burns) causes weight gain. The converse is true for weight loss. Often, the sugar-sweetened snacks we consume are composed of combinations of flour, sugar and fat, rendering them irresistible, or “hyperpalatable” in nutrition jargon, making them easy to over-consume (in other words: they’re delicious). These often contain large amounts of calories due to high fat content (fat contains over twice the calories per gram of protein or carbohydrate) and low fiber (which helps drive satiety): factors that conspire to ease over-consumption. It’s that overconsumption that can push a person into a calorie surplus over time, leading to weight gain.
The reverse, then, is true of weight loss: eliminate processed sugar-containing beverages and foods, the calories consumed fall (or are replaced by lower-calorie alternatives, such as fruit or whole-grains, which also contain more vitamins and minerals that some processed foods lack), and the weight melts away. It’s important to note here that the weight loss associated with reducing or eliminating such processed foods is a function of the total calories that are being eliminated - not the sugar content of these foods alone.
The myth that sugar is uniquely fattening, independent of calories, has many origins, and it’s a myth that’s been amplified through social and traditional media by glossing over the nuance and context that is central to any discussion on nutrition (or any scientific subject). One origin myth we’ll address briefly involves fructose, perhaps due to its presence in sucrose, or your garden variety cane sugar, and high-fructose corn syrup, often a component of soft drinks.
While chemically identical to glucose, fructose’s molecular scaffolding is slightly different, changing how it’s metabolised (2). While glucose is metabolised by all cells, fructose is largely metabolised by the liver. At doses far higher than what is physiologically practicable, fructose was shown to produce fatty liver disease in mice (2). However, data from one of the last hunter-gatherer tribes left in the world, Tanzania’s Hadza, tell a different story. The Hadza consume a high proportion of their daily calories from honey (which contains both glucose and fructose) and other carbohydrate-rich vegetables while maintaining active lifestyles (i.e, calorie burn). Human trials and meta-analyses (the gold standard for synthesising research) also indicate that sugar consumption is not associated with weight gain if calories and protein are controlled (3, 4). These studies indicate that the difference between energy consumed and burned (i.e. energy balance) is central to determining body fat (6) and risks of developing conditions such as fatty liver. In other words, fructose’s mere presence in a calorie-controlled, otherwise balanced diet, with an active lifestyle, is not enough to risk weight gain and health problems. Those are derived from an excess of calories and inadequate amounts of fiber, vitamins and minerals.
Calorie balance is an elemental feature of being alive, but incorporating its principles into everyday life is not always easy. While we don’t advocate frequently consuming sugar-rich processed foods, it is possible to lose or maintain weight while incorporating moderate amounts of sugar-containing “hyperpalatable” food into a diet, if calorie and protein limits are met.
All this begs the question: what does one do? Here’s what we advise:
Reduce, don’t eliminate. Don’t suck the joy out of life. Instead, identify 1-2 days a week where you allow yourself an indulgent, calorie-dense snack. If your meals are otherwise balanced, incorporating plenty of fruits, vegetables and protein and you maintain a consistent exercise regimen, this is unlikely to disrupt your weight loss goals. Also, avoidant food behaviour has been shown to trigger binge-eating; while mindful reduction, by contrast, can help “unsweeten” your palate and enables long-term dietary adherence. Having said that, if complete elimination works well for you - go for it, just know that it is not always necessary.
Eat it, don’t drink it. Eating is far more satiating and time-consuming, compared with drinking. This allows your body and brain the time to realise you are full. Drinking sugary beverages is a quicker process, and may induce a caloric surplus. Also, tracking your food intake, via an app such as Healthify Me or Carbon Diet Coach, can help with estimating and managing calorie consumption.
A spoonful of sugar. Mary Poppins was right - it makes the medicine go down, although food is not medicine (this is a longer discussion, beyond the scope of this article). If a little sugar added to a smoothie or a salad dressing will enable you to eat more fruits and vegetables, use it. The upside of consuming nutrient-dense foods this way far outweighs the downsides of an extra half teaspoon of sugar (which, as we’ve already established, are minimal).
Meghna leads clinical research at Nutrova, and did her Ph.D. research on regenerating bone and cartilage using stem cells
Avanti is a nutrition coach, co-owner at Repps Fitness and majored in Neuroscience & Behavior at Columbia University
REFERENCES
Norton, Layne. “Why Sugar Did Not Cause the Obesity Epidemic.” Biolayne, 10 Nov. 2022, biolayne.com/articles/nutrition/why-sugar-did-not-cause-the-obesity-epidemic/
Softic, Samir, et al. “Divergent Effects of Glucose and Fructose on Hepatic Lipogenesis and Insulin Signaling.” The Journal of Clinical Investigation, U.S. National Library of Medicine, 1 Nov. 2017, www.ncbi.nlm.nih.gov/pmc/articles/PMC5663363/.
Morenga, Lisa Te, et al. “Dietary Sugars and Body Weight: Systematic Review and Meta-Analyses of Randomised Controlled Trials and Cohort Studies.” The BMJ, British Medical Journal Publishing Group, 15 Jan. 2013, www.bmj.com/content/346/bmj.e7492.
Surwit RS; Feinglos MN; McCaskill CC; Clay SL; Babyak MA; Brownlow BS; Plaisted CS; Lin PH; “Metabolic and Behavioral Effects of a High-Sucrose Diet during Weight Loss.” The American Journal of Clinical Nutrition, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/9094871/. Accessed 4 July 2024.
Pontzer, H., Raichlen, D. A., Wood, B. M., Mabulla, A. Z. P., Racette, S. B., & Marlowe, F. W. (2012, July 25). Hunter-gatherer energetics and human obesity. PLOS ONE. https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0040503
Westwater, M. L., Fletcher, P. C., & Ziauddeen, H. (2016, July 2). Sugar addiction: The state of the science. European journal of nutrition. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5174153/