By Kelley Herring
Have you ever seen a vintage photograph from the 50s or 60s, with a crowd of people strolling on a sunny summer boardwalk or swimming and tanning on the beach?
What’s the first thing you notice?
It is impossible to miss that the average person in those decades looks a LOT different than the average person today. In fact, in most of those pictures, you would be hard pressed to find one or two people who would be considered “fat”. Most of the people in those photos are decidedly lean – and certainly by today’s standards.
By contrast, take a photo of the same beach or boardwalk today, and you would be hard pressed to find just one or two people who are considered “lean”. Almost everyone in the modern scene would be considered overweight or obese.
According to the UK National Sizing Survey, the average woman’s waistline has expanded seven inches since 1954. The same goes for men to an even greater extent, with their “Beer Bellies” and “Dad Bods”.
However, the changes in our body composition are more costly than simply changing our appearance in the mirror, because as your waistline expands… your brain steadily shrinks.
In fact, new research published in JAMA Network Open found that increased body fat equates to reduced thinking and ability to remember.[i] And it is the so-called visceral fat, packed around your abdominal organs, that has the greatest impact.
The study evaluated 6,733 participants with magnetic resonance imaging (MRI) to measure visceral fat. The MRI also assessed vascular brain injury, which results in areas of reduced blood flow in the brain.
The researchers found the total amount of body fat and visceral body fat were significantly associated with cognitive decline in the participants – even after adjusting for other factors like having diabetes or vascular brain injury. Co-author of the study, Eric Smith says:
“…. preserving cognitive function is one of the best ways to prevent dementia in old age. This study suggests that one of the ways that good nutrition and physical activity prevent dementia may be by maintaining healthy weight and body fat percentage.”
Another recent study of nearly 10,000 subjects was published in the journal Neurology. This study found that those with higher waist-to-hip ratios (larger midsections) and higher BMI (body mass index – or weight-to-height ratio), had the lowest brain volume.
Mark Hamer, PhD, of Loughborough University in Leicestershire, England.
“Our research looked at a large group of people and found obesity, specifically around the middle, may be linked with brain shrinkage.”[ii]
While weight loss can be achieved in a number of ways, all weight loss is not created equal. In fact, certain types of exercise and diet target those deep visceral stores more effectively and improve brain health better than their counterparts…
The One-Two Punch to Torch Belly Fat + Boost Brain Health
High intensity interval training (HIIT) has long been known to improve overall body composition and reduce body fat better than traditional, long-duration exercise.[iii] Similarly, a carb-restricted or ketogenic diet is also known to target visceral fat and improve body composition.[iv]
In a recent randomized crossover trial published in Cureus, researchers sought to discover how combining these two modalities could favorably impact brain health.
Twelve participants with metabolic syndrome engaged in two-four week interventions. The first was a carbohydrate-restricted Paleolithic-based diet with sedentary activity (CRPD-Sed). The next was a carbohydrate-restricted Paleolithic-based diet with HIIT three times a week (CRPD-Ex).
The interventions were separated by two weeks for a “wash out”. The Stroop Test for cognitive function was conducted and brain-derived neurotrophic factor (BDNF) – a key factor in neuronal plasticity, memory and learning – was measured.
The Brain-Boosting, Belly-Fat Torching Diet in the study consisted of:
- Unlimited amounts of animal foods (meat, fish, eggs), leafy and cruciferous vegetables, root vegetables, fruit
- Moderate amounts of nuts, dried fruit, potatoes (<1 medium-sized/d), and wine (<1 glass/d).
- No cereal grains, dairy, beans, legumes, refined fats, bakery items, soft drinks, beer, extra salt, and sugar.
- A macronutrient ratio goal of 25% protein, 60% fat, 15% carbohydrate, with carbohydrates under 50 g/d.
- No calorie parameters were specified.
Compared to baseline, both CRPD-Sed and CRPD-Ex interventions improved measures for cognitive function, with the HIIT group accruing significantly more benefits:
- Serum BDNF increase (20% vs 30%)
- Psychomotor speed and cognitive flexibility (-14% vs -14%)
- Self-perceived cognitive symptoms and functioning (+8% vs +16%)
The researchers conclude:
“We have shown that the addition of exercise can further improve neuroprotection and cognitive function beyond the results of diet alone.”
No More Counting, Dreading & Breading! Choose Intelligent Exercise & Intuitive Eating
Gone are the days of counting calories… long, slow, boring cardio… and a grain-based, brain-draining diet.
We now know that what we eat and how we move profoundly impact our energy metabolism, cognitive function, and overall health.
So, stock your freezer with the Paleo-approved, carb-restricted foods our ancestors enjoyed, including grass-fed beef, pastured pork and poultry, farm-fresh eggs, organic above-ground veggies and berries. And get started with a quick and effective HIIT workout plan – it’s a small investment that can pay big dividends for your long-term health.
Love comfort foods, but not the carbs? Check out Kelley’s FREE new book – Carb Lover’s Keto – with 100 recipes for all of your favorite comfort foods. From Chicken Parmigiana and Coconut Shrimp to Buffalo Wings and Pizza. Discover how you can indulge – 100% guilt free!
[i] Sonia S. Anand, Matthias G. Friedrich, Douglas S. Lee, Phillip Awadalla, J. P. Després, Dipika Desai, Russell J. de Souza, Trevor Dummer, Grace Parraga, Eric Larose, Scott A. Lear, Koon K. Teo, Paul Poirier, Karleen M. Schulze, Dorota Szczesniak, Jean-Claude Tardif, Jennifer Vena, Katarzyna Zatonska, Salim Yusuf, Eric E. Smith. Evaluation of Adiposity and Cognitive Function in Adults. JAMA Network Open, 2022; 5 (2): e2146324 DOI: 10.1001/jamanetworkopen.2021.46324
[ii] Mark Hamer, G. David Batty. Association of body mass index and waist-to-hip ratio with brain structure. Neurology, Jan. 9, 2019; DOI: 10.1212/WNL.0000000000006879
[iii] Cao J, Lei S, Zhao T, Xie Y, Zhou Z, Cheng S, Wang X. Changes in Fat Oxidation and Body Composition after Combined Exercise Intervention in Sedentary Obese Chinese Adults. J Clin Med. 2022 Feb 18;11(4):1086. doi: 10.3390/jcm11041086. PMID: 35207356; PMCID: PMC8879656.
[iv] Amini MR, Aminianfar A, Naghshi S, Larijani B, Esmaillzadeh A. The effect of ketogenic diet on body composition and anthropometric measures: A systematic review and meta-analysis of randomized controlled trials. Crit Rev Food Sci Nutr. 2022;62(13):3644-3657. doi: 10.1080/10408398.2020.1867957. Epub 2021 Jan 14. PMID: 33443451.